UF PHA6936 Final Exam Prep - Edited by T. Dickson

Paul Ion Trap

-3 electrodes -ring electrode separating two hyperbolic electrodes -voltage changes on the electrodes to eject ions from the trap

Drugs to use Silyating Reagents On

9-tetrahydrocannabinol, lorazepam, and genzoylecgonine

Why is pH important in toxicology?

Absorption, distribution and excretion of drugs in the body and being able to extract and analysis the drugs.

What is the only fabric to dissolve in acetone?

Acetate

The active phase of hair growth is known as ______.

Anagen

How long does it take for liver mortis to appear?

Appears 1 hr after death with full appearance in 3-4hrs.

What color is produced by Mandelin Reagent in the presence of Methadone?

Blue

To lower fusion temperature and viscosity what is added to silica?

Carbonates of sodium or potassium

Cabinet/Hood for dealing with DNA

Class II biohazard cabinet along with PCR set up cabinets

What Ionization Methods of MS are for GC interfaces?

EI and CI

The YSTR is found only on the x chromosome. (T/F)

False

The ionized form of a drug remains in the organic phase of an extraction. (T/F)

False

The laboratory does not need to suspend activities when there are severe deficiencies that greatly affect the reliability of the testing at the laboratory. (T/F)

False

Screening tests can give...

False positives

What are 2 examples of chemical properties?

Flammability, reactivity

Semen fluoresces due to the presence of _______.

Flavins

The DNA in human body fluid cells will be degraded rapidly on items (rich in microorganisms) such as:

Foliage, Soil and Carpeting

What are the specific hairs that allow a quick way to determine if an unknown is marijuana?

Glandular hairs

In a strand of DNA, cytosine (C) complementary pairs with

Guanine (G)

What is the difference between hydrophilic and hydrophobic?

Hydrophilic-water absorbing Hydrophobic-water repelling

What do forensic scientists use physical evidence for?

Identification and comparison.

Liquid typically derived from crude oil by distillation.

Ignitable Liquids

Strong Acids (Ka and pKa value)

Ka >1, pKa < 0

How to collect trace evidence:

Lifting, scraping, vacuum sweeping, combing, clipping

Hazards at the Crime Scene

Light Sources, Confined Space, Clandestine Drug Laboratories, Drug Paraphernalia, Corpses and Human Remains, Fingerprint Agents, Stress Management, Mass Disaster

What is the formula to calculate density?

Mass/Volume

The temperature that the Becke line disappears at is called

Match Temperature

Who is the Father of Toxicology?

Mateu Orfila

Examples of Schedule II Drugs

Morphine, PCP, Cocaine, Methamphetamine

Cubic Crystal Structure have how many RIs?

One

Purity and Identity of test compound

Purity verified by HPLC and identity by comparison of MS to a reference standard

Type of Mass Analyzers

Quadrupole, Time of Flight (TOF), Paul Ion Trap, Linear Ion Trap, Electrostatic Trap, Tandem MS

Which immunoassay technique is not a homogenous immunoassay? KIMS, EMIT, FPIA, RIA, or CEDIA

RIA

Which animal is most commonly used to create antisera?

Rabbit

What are the types of fracture patterns of glass?

Radial and concentric

Computer Forensics

Recover data from digital media

Sources that are exempt from Ionizing Radiation Regulation

Sealed sources, electron capture GC detector, stainless steel cylinder containing beta-emitting radionuclide nickel-63

What are the 5 steps in crime scene investigation?

Secure crime scene Observe crime scene Document crime scene Search crime scene Collection & preservation of evidence

Types of Raman Scattering

Stokes and anti-Stokes scattering

Which is NOT a universally accepted searching method in regards to crime scene investigation? Strip, Swirl, Wheel, Grid

Swirl

One of the most common confirmatory tests for blood is called:

Takayama test

Which is NOT a growth phase of hair

Telogen

What part of the spermatozoon contains DNA?

The head

Securing the crime scene area is the responsibility of whom?

The initial responding officer

Which of the following mass analyzers relies on the velocity and kinetic energy of ions for separation? Quadrupole, Ion Trap, Time of Flight, All, None

Time of Flight

What is the function of the red blood cell?

Tissue oxygenation

The basicity of any base depends on the acidity of the acid that donates the proton. (T/F)

True

UV-Vis Detectors

Variable Wavelength Detector or Diode Array Detectors (DAD)

What evidence cannot be packaged immediately? Why?

Wet evidence because it could be destroyed by mold or mildew

Negative control

a substance that will react as if the drug being tested for is not there because it is not there, ex DI Water

Colorcoat

acrylic-based polymer, needs to resist weathering from UV light and environment insults

Controlled Substance Storage

all controlled substances should be stored under lock and key and their use must be documented, most common is ethanol

What is detrimental to the survival of DNA?

bacteria, heat, moisture

Examples of Schedule IV

benzodiazepines like Diazepam, Oxazepam

Softer, smoother surface produce:

better marks than hard, brittle surfaces

Typical chemicals used to make the gradient for the density test:

bromoform and bromobenzene

Fiber - TLC

can be used in some cases to detect and compare dye components, only considered for comparisons when its not possible to discriminate between the fibers using other techniques

crime scene documentation methods do not include:

cell phone records

Weapon perpendicular to the target

circular residue pattern around the bullet hole

Physical Characteristics of Natural Fibers:

color, diameter, and miscellaneous

Major Case Prints

complete sets of prints, all parts of hand, fingertips, palm, sides of fingers and palm, feet may also be included

The middle layer of hair is:

cortex

Three trichomes/hairs on the cannabis plant

covering (clothing), cystolithic, and glandular trichomes

Swing-out revolver

cylinder rod is attached to a hinge on the side of the frame

Somatic death

death of the entity

Temperature can accelerate ...

degradation reactions

Cross-Sectional Shape of Fiber

determine by optical section, viewing the fiber longitudinally and slowly focusing through the fiber

1st step of hair examination

determine if hair, examine for cuticle scales, medulla and pigment granules

American Board of Criminalistics (ABC)

developed a series of examinations allowing the certification of individual forensic scientists in their particular area of expertise

Luke May

developed and applied analyses for tool mark comparison

Glass R I Measurement (GRIM)

electronically scans the glass edge for the disappearance and re-appearance of the Becke line as the oil is heated

X-Ray Flourescence Spectrometry (XRF)

elemental analysis technique based upon the emission of characteristic x-rays following excitation of the sample by an x-ray source

Contextual Effects

environmental influences and past experiences that can sway our decision making processes

Outer root sheath is attached to what?

erector pili muscle

Prior to applying an immunoassay technique in the lab

establish and verify a limit of detection and linear range for the method.

The Linking Principle

evidence can link the victim(s) to the suspect(s), the victim(s) to the scene(s) and the suspect(s) to the scene(s)

Mateu Orfila

father of toxicology, developed first chemical test to detect arsenic, first documented provision of legal testimony by legal medical experts

Lansteiner

first described Rhesus blood groups

Smokless powder has a variety of shapes:

flakes, disks, ball, cylinders and they may have perforations

Sensitivity

generally reported by signal-to-noise ratios or the limit of detection

As the numerical aperture of the microscope increase resulting in _________ resolution and light transmittance.

greater

Single action firearms

hammer has to be manually cocked

Two groups of firearms

handguns and long guns

Laboratory Notebooks

hardbound logs that are numbered, information is recorded by hand, notebook pages must be consecutively numbered before using the notebook, all data must be entered in indelible (permanent) ink, date, time, signature/intitials should be written after each major step, printouts from instruments or photos of gel-electrophoresis can be included

Issue with Palm Prints

hollow part of the palm may not be properly printed

Selectivity

how well components can be distinguished from one another

Mechanisms of Drug Degradation

hydrolysis, oxidation, and photochemical changes

Routine Maintenance

involves simple procedures with the purpose of protecting the equipment and/or personnel ex. replacing GC sept, rinsing an HPLC system prior to shut down to prevent build-up, disinfecting biological safety cabinet after each use, cleaning pump block on the genetic analyzer

Components of a MS

ion source, mass analyzer, detector and vacuum

Factors to consider during paint analyze

issues of the case/investigation, sample size, complexity and condition, environmental effects, and sample collection methods

Glass is elastic therefore when force is applied to a sheet,

it bends then break

Test toolmark surface is typically:

lead

Where does the inner root sheath stop?

level of the sebaceous gland

what can affect how you prepare to conduct a crime scene investigation?

location, weather, time of day

Head hairs

longest length of human hairs, usually abraded or cut tips

Simplest microscope

magnifying glass

Sample Preparation for Paint

manual or microtome sectioning, edge mounting and polishing

Victor Balthazard (1890-1899)

medical examiner, studied probability models for fingerprints, bullet comparison, animal hairs and blood spatter patterns

The inner layer of hair is:

medulla

What are the three layers of hair?

medulla, cortex, cuticle

Using cullet in a glass formula promotes:

melting and homogenization of the new batch and fining agents

Tests on Hash oil

microscope can not be done, spot test can be and TLC

Two classes of Fibers

natural and man-made (synthetic)

Natural fibers are manufactured from:

plant, animal and mineral materials

This type of fingerprint is a three dimensional impression

plastic

Examples of Non-porous evidence

plastic, glass, metal, foil

Two types of fractures in a glass fracture pattern:

radial and concentric fractures

Regenerate cellulose fibers include:

rayon and acetates

First man-made fibers were made from

regenerated cellulose

Before beginning drug analysis

sample should be accurately weighed

You have the same mitochondrial DNA as your ...

sibling and mother

A person's ____ is usually more distinctive than their normal handwriting

signature

Infrared Sources

silicon carbide Globar or nichrome coil

Scraping

spatula or other tool used to dislodge trace materials onto clean paper, debris is then packaged in a way to avoid sample loss, typically conducted at the laboratory

Flammable Chemicals

stored in flammable cabinet according to their labels.

Asian Ancestry "Mongoloid"

straight with circular cross sections, deeply pigmented, thick cuticles

The cortex provides:

strength and color and texture to hair

Arthur Conan-Doyle

suggested that soil collected on a person at a crime scene could be used as evidence to place that person at the location

Purpose of a final report

summarizes the work, provides interested parties information, documents that the laboratory has accomplished the task that it was funded, provide a record to the court of the results of forensic examinations

Shotgun wadding

surround the pellet to protect the shot from the hot gases produced, consists of paper, felt or plastic

After visual examination of the fiber evidence what collection methods would be employed?

tape lifting or scraping

Marijuana

term for the plant material from Cannabis sativa

Why is laminated glass used as a safety glass in vehicle windshields?

the plastic adheres tightly to the glass and holds the broken pieces in place

Wavelength Selector- Refraction Grating Monochromators

these have a reflective surface etched with small grooves, when light enters the monochromator it strikes the grating at an angle and is dispersed, unlike the prism monochromator this provides linear wavelength dispersion along the focal plane of light.

Dermis

thick layer of connective tissue with blood vessels, provides nutrients and blood to the epidermis

The cuticle is

thin, colorless and protects the cortex

TLC: Mobile Phase

this phase is dependent on the class/classes of drugs to be separated and the type of stationary phase chosen

Fingerprints are formed where:

tips of fingers, toes and palms

Soda (sodium carbonate) is included ...

to lower the melting point and viscosity

Sample Cells (UV-Vis)

transparent cuvettes, depending on wavelength used made from, quartz, fused silica, glass or plastic, same cuvette used for reference and test samples

Liquid-Liquid Extraction (LLE)

using an organic and aqueous solution to separate a drug from the matrix

Epidermis

varies in thickness, no blood vessels

Disadvantages of Fluorescence

very few compounds are naturally fluorescent most can be derivatized to incorporate a fluorescent label

Issues with presumptive tests

very sensitive possible false positives, and does not identify individuals but class characteristics

Reference Standard Authenticity

when investigating an unexpected result, comparing to known results ex. comparison of known retention times or peaks at certain masses

Radioimmunoassay (RIA)

- heterogenous - 1st developed -competitive -uses radioactively labeled antigens -several wash steps needed -detector must detect radiation -inversely proportional

Fluorescence Polarization Immunoassay (FPIA)

- homogenous -competitive -fluorophores absorb 485nm and emit 525-550 nm -maintain polarized light throughout -Unbound antigens are smaller molecules that rotate more the emitted light becomes depolarized so the light is blocked by the filters -Bound antigens are larger molecules that rotate less the emitted light does not become depolarized and passes through the filter -inversely proportional to response

Flame Ionization Detector (FID)

- hydrogen and air flame -compounds pass into the flame -causes organic molecules to become ionized -which results in a detectable current detector response is proportional to concentration of analyte -does not allow identification since no structural information given

Wavelength Selector-Monochromator

- variable entrance slit, a rectangular optical image from the light source -a collimating lens or mirror that produces a parallel beam of radiation -a prism or refraction grating to disperse the radiation into its component wavelengths - a focusing element the reform the image -an exit slit that isolates the spectral band

Instrument Qualifications

--Consider the required level of precision and accuracy prior to purchase --Think about the working enviro (electrical, plumbing) and space needed --Technical and service support provided? --Price-new and replacement parts --# and size of samples, speed of analysis --installation? --operation? installed by vendor? --how many units of this instrument will we need? --special considerations (temp, DNA reagents should not be stored in freezer that has auto thaw)

Equipment file includes:

--equipment qualification --calibrations --preventive maintenance --performance qualification testing

Components of Analytical Procedures (4)

--extraction of the test compound from a matrix --construction of a standard curve --quantitation of the test article --quality control of the analytical process

Examples of General Standard Operating Procedures (SOP's)

--prep of bleach soltn --Prep of soltns --Deter sig figs --Receipt and Inspection of Sample/test article --use and operation of balances, pH meters, fume hood, measuring pipettes --preventive maintenance --limitations of method

Study Protocol-Experimental Plan

--this includes: the #, weight range, sex, source of supply, species, strain, sub-strain and age of all animals used --IACUC approval-use of animals must be reviewed and approved --info presented to the IACUC would include: conditions, descript of animal cages, feeding, provisions, treatments and experimental use, disposal of study animals, disposal of animal by-products, procedures for adverse events. --use of human subjects requires Institutional Review Board (IRB) to approve --#, sex, age, and criteria for selection of human subjects. use of fetuses, children, pregnant women, and prisoners is restricted --An informed consent form must be read, signed and dated by all human participants. Must be written so all participants understand it. --Procedure for ID to the system, using specific criteria to select the test system

Electrostatic Trap

-3 electrods -two on each end and one in the center -ions enter and are trapped -sent into an oscillation around the center electrode and between the two end electrods -separation because they oscillate at different frequencies -m/z measured based on frequencies

Atmospheric Pressure Chemical Ionization (APCI)

-CI version of ESI -gas and heat aerosolize the liquid -spray of liquid interacts with a strong electrical field capable of ionizing the solvent -solvent passes the charge to the analyte -remaining solvent evaporates, and sample is passes into mass analyzer -+/- can be used

Detectors for HPLC

-UV-VIS -Diode Array -Fluroescence -Electrochemical -FTIR -Mass Spectrometer

Direct Analysis in Real-Time (DART)

-at atmospheric pressure -little to no sample prep --exposed to heated, electrically charged gas -gas comes into contact with water vapor creating protonated water clusters containing metastable ions -ions react to ionize the sample using helium -negative mode can be used also -heating of ionization gas is critical to ensure that no thermal degradation takes place

Crime Scene Investigators should be effective managers:

-at the scene of the crime/incident -of the processing of physical evidence collected from the scene -of the investigative process as it relates to physical evidence -of the final presentation of physical evidence at court

Electrospray Ionization (ESI)

-capillary tube that the eluent goes through -voltage applied to the end of the tube -aerosols the liquid into electrically charged droplets using a nebulizing gas -negative ions drawn back to positively charged tube -positive ion thrust forward -positive ions desolvate by the nitrogen gas and break apart further - + ions propelled to the negatively charged entrance into the mass analysis

Kinetic Interaction of Microparticles in Solution (KIMS)

-competitive -homogenous -labeled antigen-microparticle conjugates -labeled antigen binds to antibodies forming a cross-linked molecular lattice blocking transmitted light -labeled antigen not bound to antibodies the lattice decrease and more transmitted light goes through -inversely proportional

During layer examination what should be considered?

-considerable consistency of composition with other models produced around the same time -different vehicle makes and models with the same paint color and composition -more layers the better, -resprayed, better chance for individualization -number and thickness of layers may vary at differ sites on the vehicle body

Light Source

-continuum light source is used -Typically Hydrogen or Deuterium lamps for UV, UV range = 160-175nm -Tungsten (W) lamps are the most common for Vis and Near IR, Range = 350-2000nm

Physical Evidence

-describe all physical materials examine in the forensic laboratory -synonym for trace evidence

Enzyme-Linked Immunosorbent Assay (ELISA)

-enzyme-linked antigens -competitive or non-competitive -heterogeneous -uses a substrate to induce a color change -uses stop reagent to end the color change -inversely proportional

Electron Impact (EI)

-filament that is heated and then produces a bean of electrons -interact with the analyte and remove an electron from their outer shell -fragmentation continues -conducted under vacuum to help fragments move towards mass analyzer -harsh ionization method -GC interface

Quadrupole

-four parallel rods -different applied electrical potentials -fixed positive or negative DC -superimposed radio frequency - electric field only allows certain m/z to enter the detector -DC and Rf conditions are varied and the spectrum is obtained

Cloned Enzyme-Donor Immunoassay (CEDIA)

-homogenous -competitive -Enzyme donor (ED) smaller piece, attached to the antigen -Enzyme acceptor (EA) large piece, in the substrate -ED bound to antibody then EA will not be able to combine -ED not bound to antibody then EA will combine and become active -Active enzyme reacts with substrate to produce color change (yellow-orange to deep red) -Directly proportional

Enzyme-Multiplied Immunoassay Technique (EMIT)

-homogenous -enzyme oxidizes the substrate and reduces the cofactor -enzyme bound to antibodies oxidation and reduction abilities are inhibited -reduced cofactor is what is measured -directly proportional to amount of drug -liquid phase assay -mostly used in screening for synthetic drugs

Time of Flight (TOF)

-ion are shaped into a beam -beam is subjected to a high voltage pulser to accelerate the ions into the flight tube -ion move through the tube and are separated based on kinetic energy they gain from the acceleration -smaller ions reach the detector first -reflectron is used to correct ions velocities enabling better resolution -TOF is from entry to the tube to reaching the detector -TOF is converted to m/z -detect to four decimals the exact mass of the ion

Triple Quadrupole

-ions travel through first quadrupole only targeted ions are allowed through -ions then go through a second quadrupole with Rf only, acts as a collision cell, collision gas interacts with ions to cause fragmentation -then go through the third and final mass filter, where a secondary targeted ions are sent through to the detector

Matrix-Assisted Laser Desorption Ionization (MALDI)

-organic particles with strong absorption for the laser wavelength is the matrix -solution dried and deposited onto a stainless steel plate -hit with a laser causes the matrix to heat -portion of the matrix and sample are ablate and vaporized -sample undergoes proton transfer and is ready for mass analysis -can be done under atmospheric pressure

Disadvantages of Vacuum Sweeping

-rigorously cleaned between uses -new parts of each area -high probability of cross-contamination

Chemical Ionization (CI)

-same instrumentation as EI -add reagent gas first interacts with the electron beam - +/- charged ions created -type dependent on reagent gas -molecular ion is preserved -GC interface

Mass Spectrometer (MS)

-sample is bombarded with electrons -fragmenting the molecule -separated by mass to charge ratio (m/z) -records amounts of each -creating a spectrum that is characteristic for every compound (identification)

Important Aspects of Crime Scene Investigation:

-securing and protecting the scene -prevention of contamination -preservation of physical evidence

Initial Entry of the Scene What should be considered?

-use an entry other than taken by the suspect -establish the path taken by other persons first on the scene -consider loss of trace evidence on entry throughout your examination -Reassess Occupational Safety and Health (OSHA) issues -Establish the extent of the scene and additional assistance that may be required -establish an entry and exit path of those who need to access to the scene

Atmospheric Pressure Ionization Methods (API)

-used for liquid samples -analytes are desolvated and/or ionized at atmospheric pressure -outside vacuum -then ionized -then pumped to the mass analyzer

Disadvantages of Latent Prints on Skin

-washed away from perspiration -exposed to harsh conditions: mutilation, contamination with body fluids, weather effects and decomposition -crime scene processing, several people may handle the body, destroying and adding prints to the skin -refrigeration and temperature can negatively effect the outcome of processing

What is the range for pH?

0-14

How often does hair grow?

1 cm/month

Poor Quality Management can result in or be the cause of...

1. Lacking attention to detail 2. Understaffed 3. poor workload management 4. non-validated tests 5. quality control and assessment 6. poor sample control 7. poor results verification

Chain of Custody Documents

1. a transmittal document to describe field activities and receipt of the samples 2. a document that records storage and disposal of activities 3. a document that follows the sample through its analysis

Internal Validation FBI Studies Required

1. accuracy, precision, reproducibility 2. locus must be defined and characterized 3. species specificity 4. sensitivity, stability and mixture studies 5. database and independence testing 6. allele and frequency distributions determined 7. non-probative sample study 8. match criteria established

Why would Beer's Law be non-linear?

1. electrostatic interactions between molecules in close proximity 2. scattering of light due to particles in the sample 3. fluorescence of the sample 4. changes in the refractive index at high concentration 5. non-monochromatic radiation 6. stray light 7. non-homogenous sample 8. reaction of the sample with the solvent

Methods to avoid obsolescence of data

1. keep original software, operating system, and all associated hardware 2. program all future computers to emulate the original software and operating system 3. Copy the record from the old format to the new one-migration

Two important aspects of sampling

1. sample should representative of the entire amount 2. is there heterogeneity of the analytes in the batch

What resolution is desirable to avoid possible interference of one peak with another?

1.5

What does deci mean?

1/10

What does centi mean?

1/100

What does milli mean?

1/1000

Medullary Index for Animals

1/2 or greater

Medullary Index for Humans

1/3

What does deca mean?

10

What does hecta mean?

100

What does kilo mean?

1000

Signal to noise ratio to estimate LOQ

10:1

How many hours post mortem does rigor mortis become fully present?

12

John Glaister

1700 photomicrographs that show the structure of hair of humans and other mammals and their relation to criminal investigation

How far away could objects and people be to still have GSR on them?

2 meters

Compound Microscope

2 or more lenses one being the upper eyepiece and the second the lower one the objective.

How long does rigor mortis last?

2 to 3 days

Rigor mortis remains for ____ then disappears again.

2-3 days

Hoods

2.5 linear feet of hood per person for every two people that work regularly with chemicals, need to have continuous flow-monitoring device, a special fume hood is required for perchloric acid use

What percentage of the population are considered to be non-secretors?

20%

Ultraviolet light has the wavelength range:

200-400nm

Hair Standard

30 preferable 50 hairs with representation from all over the scalp

Signal to noise ratio greater than ____ is used to estimate LOD

3:1 or 2:1

Automobile paint consists of at least ____ layer

4

Automobile paint typically has a minimum of ___ layers. (Plastic doesn't exist!)

4

Protein hemoglobin absorbs light at:

400 nm

Microspectrophotometry - Fibers

5-10 locations along a fiber or groups of fiber for representative mean absorbance curve and standard deviation curves. Synthetic fibers typically need less scans to produce good results than natural fibers

Sample amount needed for PGC

5-10 micrograms

When taking reference samples from the head, how many hairs do you need?

50 full length hairs

Rigor mortis appears ____ after death.

6-12 hrs

Sample Log In to Lab

A chronological log of all samples should be maintained with the following info: date sample was collected, date sample was received, unique laboratory ID #, cross-reference to original field #, required analyses, signature or initials of person logging the info, comments on sample integrity ID #'s should be on sample ctgr not lids

The light source for dispersive infrared spectrophotometers usually consists of:

A silicon carbide Globar

Unknown fingerprints are entered into the data base as:

AFIS

If you inherit type A from your mother and type O from your father what is your resulting genotype?

AO

Paint smears can be sampled uses

ATR accessory or ATR objective on an infrared microscope

Beer-Lambert Law (commonly Beer's Law)

Absorbance (A) = molar absorptivity (e)times concentration (c) times path length(b)

Screening tests for semen are based on detecting the enzyme ...

Acid phosphatase

Who was responsible for courts acceptance of documents as scientific evidence?

Albert Osborn

What is the most abundant protein in blood serum?

Albumin

Standard PPE includes: Hand Protection, Foot Protection, Eye Protection, All

All

During crime scene processing which type of evidence is collected first?

All fragile evidence

Experimental design in study protocols is concerned with obtaining data in a statistically relevant manner, which mean the following items should be done: The number of samples or subjects must be sufficiently large to provide a representative set of data the variables must be controlled a measurement is preferred over an observation all of the above

All of the above

In the laboratory a drug sample that is a false negative is associated with: failure of the analytical test can result in critical data being lost is considered a less serious error than a false positive all of the above

All of the above

What types of swabs are most common in sexual assault kits? Vaginal swabs, anal swabs, oral swabs, all of the above

All of the above

When securing a crime scene, boundaries typically start at the focal point of the scene and extend outward to include: where the crime occurred, potential points of entry and exit of suspects and witnesses, places where the victim or evidence may have been moved, all of the above

All of the above

When using an orange filter on an alternative light source, which biological fluid will fluoresce white? Vaginal secretions, semen, urine, All of the above

All of the above

Which of the following reagents is a protein stain? Ponceau red, Coomassie blue, Amido Black, All of the above

All of the above

Which presumptive test for blood reacts with blood proteins to give a light to medium blue color? Luminol, Leucocrystal Violet, Amido Black, Bluestar

Amido Black

What is the most conventional treatment for blood fingerprints?

Amido black

The best screening test for saliva is ____.

Amylase mapping

What is the best stage for DNA comparison of hair?

Anagen stage

What are th 3 stages of growth?

Anagen, catagen, telogen

How long does each stage of growth last?

Anagen- up to 5 years Catagen- 2-3 weeks Telogen- 2-6 months

Document Examiners

Analyze ink, paper, toner in questioned documents

What type of fibers contain proteins?

Animal fibers

FBI Questioned Documents Units Files

Anonymous Letter File, Bank Robbery Note File, National Fraudulent Check File, Office Equipment File and Watermark File

Stability

Any conditions that might be detrimental to the stability of the analyte or its extract should be assessed and included in the report such as pH, temp, humidity, calibration curve, control and subject samples, storage effects. Either needs to be assess in development or validation or use peer-reviewed literature

Polar drugs tend to be in which LLE phase?

Aqueous phase

Which vessel is under the most pressure in the circulatory system? Artery, Vein or Capillary

Artery

What are examples of mineral fibers?

Asbestos, rock wool, fiberglass

How to store a liquid sample?

At an appropriate temp (fridge/freezer), protected from light and air.

Residues can be examined by:

Atomic Absorption (AA), Neutron Activation Analysis (NAA), or Scanning Electron Microscopy (SEM) with X-ray analysis

The fingerprint database is called:

Automated Fingerprint Identification System (AFIS)

Silyating Agents for GC

BSTFA to derivatizing compounds that contain carboxylic acid, amide, phenolic, or OH groups highly volative and sensitive to moisture

How do you decide what pattern to use?

Based on size/location of crime scene and number of investigators.

What is refraction?

Bending of light as it moves from one medium to another Example- air to water

Which of the following tests has the potential to be the most harmful and therefore is not commonly used? Tetramethylbenzidine, phenolpthalein, benzidine, luminol

Benzidine

Which of the following tests has the potential to be the most harmful and therefore is not commonly used? Tetramethylbenzidine, phenolpthalein, benzidine, luminol

Benzidine

Who is credited with being the first to use latent prints in a criminal case, as well as being the first to use systematic crime scene photography for recording a scene?

Bertillon

Dreyfuss Case

Bertillon testified the accused had written a document that was the basis for the charge of treason the accurser's innocence was later proven

When performing the sulfur test, what color precipitate should show a positive outcome?

Black or dark grey

What color does tetramethylbenzidine turn in a positive reaction?

Blue

What color is produced by Cobalt thiocyanate reagent in the presence of Cocaine?

Blue

What color is produced by Marquis' reagent in the presence of MDMA?

Blue to black

Which is not a mass spectrometry ionization method? FABS, CEDIA, MALDI, EI

CEDIA

The national DNA database is called

CODIS

Key Parameters of the Validation an Analytical Procedure (16)

Calibration Model (Linearity, Calibration Range) LOD (Sensitivity) LOQ Accuracy and Precision Interferences Studies (Selectivity, Matrix Effects) Ionization Suppression/Enhancement (LCMS) Carryover Stability Robustness and Ruggedness Dilution Integrity Measurement Uncertainty Purity and Identify of Test Sample Homogeneity of solutions Extraction Recovery Specificity Quality Control

Ionization in a mass spectrometer produced by collision of the analyte with gas molecules is known as:

Chemical ionization

Chemical Storage

Chemicals should not be exposed to direct sunlight, heat source, or stored under the sink, bottles should be placed below eye level, and in cabinets with see-through doors. Separate chemicals that could react together.

Two forms of cocaine are

Cocaine HCl, Crack cocaine (free base)

Ways of ingesting cocaine

Cocaine HCl: snorted (insufflated), or injected Crack: smoked

Which of the following compounds is not considered to be acidic? Codeine, Aspirin, Ibuprofen, Penicilin

Codeine

Jeffreys' DNA Profiling techniques were used in what case?

Colin Pitchfork

What type of compounds are more likely to fluoresce?

Compounds with flat rigid structure with high concentrations of delocalized electrons

SPE Extraction Sequence (5 steps)

Conditioning the Column, Changing the pH Environment, Load, Wash, Elution

What type of medullas do humans usually have?

Continuous, fragmented or absent

Which layer has pigment granules?

Cortex

What are examples of cellulose fibers?

Cotton, rayon, cullulose acetate

What are some examples of natural fibers?

Cotton, wool, silk, hemp

Which crimes do we place more investigative emphasis on?

Crimes against people

Which layer is resistant to chemical decomposition?

Cuticle

What are the 3 layers of hair?

Cuticle, cortex, medulla

For the physical development of fingerprints, what is the name of the chemical that reacts with amino acids, fatty acids, and proteins in the latent print and the moisture in the air, then producing a visible, sticky, white material along the ridges of the fingerprint?

Cyanoacrylate Fuming

A signal-to-noise ratio greater than ____ is generally considered acceptable for estimating the limit of detection. A. 1:1,B. 3:1, C. 2:1, D. Both B and C

D. Both B and C

When using DNA analysis for species determination the DNA probe used is known as: D40MER, SWD17, D17Z1, SWMER17

D17Z1

Ionization in a mass spectrometer produced by a high energy beam of neutral atoms is known as:

DART

What ionization methods of MS are used for neither GC/LC interfaces?

DART

Sequential process for a paper surface:

DFO, ninhydrin, and PD last

Bias has been found in:

DNA interpretation, latent print analysis, forensic anthropology and bloodstain pattern analysis

Electronic Records-Life expectancy

Data Storage Type Life Expectancy Magnetic tape 5-20 yrs CD-ROM 2-100 yrs Paper 20-100 yrs Microfilm 10-200 yrs

Surface tension ______ the surface area of a drop of blood?

Decreases

Classification of Loops

Delta, Sufficient recurve, ridge count, radial/ulnar loops

Three steps of PCR:

Denaturation, Primer Annealing, Elongation

What are 2 examples of physical properties?

Density, color, texture, odor

Parts of a study protocol

Descriptive title (ID #, status (draft, pending), approval date) Study Objective (purpose of study-dose confirmation, dose determination ,concentration of by-product Identification of the Test and Control Articles (by name, chemical abstract # or code) Sponsor (indv, organization, or testing facility that supports the study and all their contact info) Testing Facilities (the person or laboratory that actually conducts the experiments) Others involved Justification for Study (info given to justify the study objectives ex. published work

Psychology/Psychiatry

Determine competency of a suspect to stand trial

Anthropology

Determine if bones are human or animal

Odontology

Determine skeletal remains through dental records

Entomology

Determine time of death using insects

Toxicology

Determine whether drugs are in a human body

Automated database systems

Drugfire and IBIS

Why does TLC enable separation of drug mixtures?

Drugs will travel at different rates due to solubility in mobile phase, hydrogen bonding capabilities, and degree of ionization (pKa)

Why will two glass objects not break the same way?

Due to the amorphous nature of glass

Uses a charcoal matrix that the air from the evidence container that is fitted with a modified lid is drawn

Dynamic Headspace

What anticoagulant compound was found in blood samples in the OJ simpson case?

EDTA

What is resolution related to?

Efficiency, selectivity, and retention

The general principle of gel electrophoresis is to separate molecules based on:

Electrical charge

Which of the following HPLC detectors is sensitive to pg/mL levels? Mass spectrometer, Fluorescence, UV/VIS- Variable Wavelength, UV/Vis-Diode Array, Electrochemical

Electrochemical

Ionization in a mass spectrometer produced by an electron beam is known as:

Electron Impact

Which of the following is considered to be a harsher ionization technique due to the potential for extensive fragmentation? Electron Impact, MALDI, Electrospray, Chemical Ionization, DART

Electron Impact

Types of MS Ionization Methods

Electron Impact (EI), Chemical Ionization (CI), Matrix-Assisted Laser Desorption Ionization (MALDI), Electrospray Ionization (ESI), Atmospheric Pressure Chemical Ionization (APCI), Direct Analysis in Real-Time (DART),

Type of Detectors for GC

Electron capture detectors (ECD) Flame Ionization detectors (FID) Thermal Conductivity detectors (TCD) Nitrogen-Phosphorus Detector (NPD) Mass Spectrometers (MS) Infrared spectrophotometers (IR)

Ionization in a mass spectrometer produced by using a fine needle and a spray is known as:

Electrospray

Which step of DNA amplification involves the use of DNA (TAQ) polymerase?

Elongation

Types of Immunoassay:

Enzyme-Linked Immunosorbent Assay (ELISA), Radioimmunoassay (RIA), Enzyme-Multiplied Immunoassay Technique (EMIT), Fluorescence Polarization Immunoassay (FPIA), Kinetic Interaction of Microparticles in Solution (KIMS), Cloned Enzyme Donor Immunoassay (CEDIA)

The following drug is NOT a known cross-reactor on Cannabinoids immunoassays: Naproxen, Ephedrine, Ketoprofen, Tolmetin

Ephedrine

What are the roles of an expert witness?

Establish credibility through credentials, background experience. Evaluate evidence. Render an opinion about the evidence.

_____ , _____, _____ boundaries to the scene will prevent the alteration or destruction of physical evidence, by restricting movement, location and activity.

Establishing, defining, and controlling

What is the difference between individual characteristics and class characteristics?

Exact identity compared to a common origin

The cellulose-based paper, used for the storage of whole blood, that prevents DNA degradation and microbial breakdown is known as: EDTA paper, STR paper, Nucleic acid paper, FTA paper

FTA paper

A basic substance can only behave as a base when in the presence of other bases. (T/F)

False

A hapten forms the primary immune response and functions to resist disease. (T/F)

False

A hapten is a monoclonal antibody produced via hybridoma technology. (T/F)

False

A hapten is a protein recognized by the body's B cells as being a foreign body. (T/F)

False

Acidic substances can only behave as an acid in the presence of other acids. (T/F)

False

Acids and bases are neutral compounds never encountered in an ionized state. (T/F)

False

Adenine is a pyrimidine base. (T/F)

False

Base peak is always the molecular ion (T/F)

False

Capillaries deliver oxygenated blood to the veins. (T/F)

False

Chemical processing of latent prints should be used if visual techniques work. (T/F)

False

Color tests are confirmative tests. (T/F)

False

Crime scene processing is the same as crime scene investigation.

False

Cytosine pairs with Adenine. (T/F)

False

DFO can be used for blood prints on porous surfaces and do not need to be visualized and photographed under UV light. (T/F)

False

DNA forms a triple helix. (T/F)

False

EMIT has a low false positive rate, works over a narrow range of concentrations, and is prone to absorbance effects from adulterants. (T/F)

False

Each drug only produces one crystal form in microcrystal tests. (T/F)

False

For ELISA a disadvantage is that it is not very adaptable to high speed analyzers. (T/F)

False

Glass conducts both heat and electricity well. (T/F)

False

Gloves worn to protect latent prints are typically made of latex. (T/F)

False

Gunshot residue analysis of a firearm should take place after biological screening. (T/F)

False

If a sample is degraded the chances of obtaining a mitochondrial DNA profile is less than obtaining a nuclear DNA profile. (T/F)

False

Immunoassay techniques can only be used to detect drugs in urine samples. (T/F)

False

Immunoassays can only be used for blood and urine specimens. (T/F)

False

In CEDIA, the signal generated by the active enzyme substrate is indirectly proportional to the amount of free drug in the test tube. (T/F)

False

In DNA electrophoresis, the negatively charged fragments of DNA move away from the anode towards the cathode. (T/F)

False

In EMIT, the binding of enzyme-labeled drug to the antibody increases the activity of the enzyme producing a color change. (T/F)

False

In FPIA, binding of the drug molecule to the antigen increases the amount of rotation and decreases the intensity of polarized light in a particular plane. (T/F)

False

In FPIA, polarization is inversely proportional to the amount of bound labeled drug and directly proportional to the amount of free drug present. (T/F)

False

In TLC, mobile phase composition is not dependent on the class/classes of drugs to be separated and the type of stationary phase chosen. (T/F)

False

In TLC, silica gel as a stationary phase is composed of uniformly distributed particles and is weakly basic in nature. (T/F)

False

In immunoassays, amphetamine and methamphetamine are susceptible to cross-reactivity from meperidine, diphenhydramine, and chlorpromazine. (T/F)

False

In liquid-liquid extraction, a disadvantage is that immiscible solvents are not required. (T/F)

False

In liquid-liquid extraction, a disadvantage is that it does not require large volumes of solvents. (T/F)

False

In liquid-liquid extraction, a disadvantage is that it does not take a lot of time to complete. (T/F)

False

Ionized forms of a drug are more lipophilic than the unionized form of a drug. (T/F)

False

It is acceptable to have pre and post amplified DNA in the same work area. (T/F)

False

It is not possible to examine a document to see what printer or copier it could have originated from (T/F)

False

Liquid-liquid extractions always utilize small volumes of solvents.(T/F)

False

Luminol is the agent of choice for detecting the presence of blood stains. (T/F)

False

Luminol is used to search for bloodstains and is not considered a presumptive test. (T/F)

False

Mitochondrial DNA cannot be analyzed in cases of mass disaster using burned or highly degraded samples. (T/F)

False

Mitochondrial DNA is inherited strictly from a persons father. (T/F)

False

Monoclonal antibodies can link to several antigen's epitopes. (T/F)

False

Once a sample is logged into a forensic laboratory it can be stored next to reference samples in an unsecured location. (T/F)

False

Once a sample is logged into a forensic laboratory the identification number for the individual sample can be placed on the lid. (T/F)

False

Once a sample is logged into a forensic laboratory the sample can be identified as occupying a certain location in a test tube rack. (T/F)

False

Pencils, fiber and ballpoint pen writings are able to be traced back to the specific one. (T/F)

False

Perspiration composition is the same between people and even within the same person. (T/F)

False

Physical struggles are not likely to result in the transfer of some trace DNA evidence from subject to victim. (T/F)

False

Polymorphic enzymes have the same structural forms of an enzyme with the differing functional properties. (T/F)

False

Preventative maintenance usually involves simple procedures intended to protect the equipment and/or personnel. (T/F)

False

Proton transfer can only occur in water. (T/F)

False

Pushing a tool into the surface makes a striated tool mark (T/F)

False

Questioned document examiners prefer to work with copies so they do not damage the original document (T/F)

False

RFLP analysis uses less sample than current STR analysis. (T/F)

False

RIA is an example of a homogenous immunoassay. (T/F)

False

Red cell Ag=A + Serum Ab = B -> ABO type is B (T/F)

False

Sliding a tool into the surface makes an indented tool mark (T/F)

False

Solvent/Microchemical Tests are non-destructive. (T/F)

False

Solvent/microchemical tests are confirmatory tests. (T/F)

False

Sudan Black will not enhance glue-developed latent prints. (T/F)

False

The measurement of uncertainty will never be recalculated once calculated in the validation study. (T/F)

False

The phenolpthalein presumptive test is more sensitive than luminol. (T/F)

False

The primary use of TLC is as a confirmatory technique. (T/F)

False

The protection of onlookers is on of the most important aspects of crime scene investigation? (T/F)

False

The relative strength of an acid or base is not affected by the solvent environment. (T/F)

False

There is a confirmatory test for the presence of saliva (T/F)

False

There is a scientific way to precisely determine the time of death (T/F)

False

There is an analytical technique that has successfully individualized a hair sample. (T/F)

False

There is little or no interference from impurities during crystal formation. (T/F)

False

Toolmark analysis of a firearm should take place prior to biological screening. (T/F)

False

When at the crime scene, the location of the CSI team at the scene should be recorded via photography. (T/F)

False

When searching for the origin of a fire; air currents, walls and stairways have no influence on a fire's spread. (T/F)

False

When searching for the origin of a fire; combustible materials decrease the intensity and extent of the fire. (T/F)

False

When searching for the origin of a fire; fires burn downwards and inwards. (T/F)

False

You can identify exact weapon basis on class characteristics. (T/F)

False

pH cannot affect the degree of drug ionization. (T/F)

False

In GC/MS, the most abundant ion is usually assigned a relative abundance of 100%; it is known as the molecular ion. (T/F)

False, it is known as the base peak

Hairs are not mounted in a medium with a refractive index close to that of the hair. (T/F)

False, it is mounted in the medium

Chemical Processing is down in the field. (T/F)

False, its done at the laboratory

X-ray ratios of elements can be used quantitatively. (T/F)

False, only comparatively or qualitatively

The partition coefficient (K) of a drug can be calculated from the concentration of the drug in the aqueous phase divided by the concentration in the organic phase. (T/F)

False, organic phase divided by the aqueous phase

larger the diameter and density of the residue pattern the closer the gun was to the target when it was fired. (T/F)

False, smaller the diameter the closer the gun

Serial Numbers won't be lost with continued etching. (T/F)

False, they can be lost with continued etching

Silica gel as a stationary phase is composed of uniformly distributed particles and is weakly basic in nature. (T/F)

False, weakly acidic in nature

What are natural fibers?

Fibers made from animals or plants

Field Samples

Field--defined as a location other than the lab Field Documentation of samples---must be recorded in ink on bound notebook that have numbered pages, info for each sample should include: date and time of collection, name of person collecting sample, ID#, documentation that sample collection materials are clean, secure sample under specified conditions Collection of Forensic Samples (ex. urine)--consider the privacy of the individual and the integrity of the sample 1. specified toilet facility used 2. add a colored cleaning agent to the toilet, prevents dilution of sample 3. remove running water and soap from the toilet facility 4. receive specimen immediately 5. check specimen temp, seal ctgr, personnel and subject should initial the ctgr

This is NOT a fundamental principle of fingerprinting

Fingerprints are formed when someone is about five years old

Which type of test is frequently done with recovered firearms to evaluate the possibility of accidental discharge?

Firearms Function Testing

What court case in 1923 set the "general acceptance" of scientific evidence?

Frye vs. United States

Three IR Vibrational Modes

Fundamental, Overtone, Combination

The most common instrument used to give an indication of the type of accelerant used to start a fire is:

GC-MS

Gunshot residue (GSR) testing can be difficult to perform because...

GSR particles do not travel far, can be washed off and only last a few hours

What is the SI unit for mass?

Grams

What are the 4 search patterns for crime scenes?

Grid, quadrant or zone, spiral, line or strip

If you are a secretor, what antigens would you secrete if you were type O? A, B or H antigens

H antigens only

How to remove drugs that are bound to proteins?

Heat the sample in acid or incubate with proteinase enzyme

What types of biological samples should never be stored in plastic containers for more than two hours? Heavily soaked blood stained items, bone fragments, teeth, stomach contents, All of the above

Heavily soaked blood stained items

Four main ways to create rifling:

Hook, broach, button, hammer

Brainstem Reflex Tests

If brainstem is dead: very bright light shone into the eye, pupil should not react firm pressure applied to cornea to elicit blinking, no corneal reflex ice cold water passed into ears to cause reflex eye movement, no movement cranial nerve motor responses should be absent, no reflex grimacing to painful stimulus suction catheter passed into windpipe no coughing or gag reflex

Microbial contamination

In any sample containing water

What is cross-reactivity good for?

In detecting classes of drugs

Three basic principles of fingerprints

Individual characteristic, remain unchanged throughout a person's lifetime, general ridge patterns allow them to be classified and used in personal identification

How do you package evidence at a crime scene?

Individually, allow wet objects to dry

Disposal of Records

Information that can be used to ID a human must be destroyed, provisions may need to be made for the off-site storage of non-active and permanent records

What does observing a crime scene involve?

Initial walk through Plan of action

Components of HPLC

Injection System, Pump, Columns, Detectors

How can the medulla be classified?

Interrupted, fragmented, continous, stacked, absent

Engineering

Investigate structural failure and investigate accidents

Precursor Ions

Ions that leave the first quadrupole

What two scientists were known for devising experimentation for blood types?

Karl Landsteiner and Leon Lattes

Strong Bases (Kb and pKb value)

Kb > 1, pKb < 0

What protein makes up the hair shaft?

Keratin

Who is responsible for the coaching and mentoring of the staff as well as the technical performance of the analyses, the interpretation, analysis, documentation, and reporting of results? Quality Manager, Laboratory Director, Technical Manager, Support System Manager

Laboratory Director

The ABO blood typing system was developed by whom?

Landsteiner

The agglutination of red blood cells with human sera was first observed by?

Landsteiner

Prints that can be seen with enhancement techniques

Latent prints

What is the SI unit for volume?

Liter

Three basic ridge patterns

Loops, Whorls, Arches

Hyperchromic effect

Loss of fine structure and an increase in molar absorptivity

What part of the body does livor mortis occur?

Lowest Extremities

Ionization in a mass spectrometer produced by using a laser is known as:

MALDI

What ionization methods of MS are for LC interfaces?

MALDI, ESI, APCI

Which powder is economical?

Magnetic

What is the function of albumin?

Maintain appropriate osmotic pressure

What is a felony?

Major Crime

How should you collect fiber evidence?

Make tape lifts, bag evidence individually, removed fibers should be folded into a sheet of paper and stored in a paper bag

What are synthetic fibers and what would be an example?

Manmade or altered fibers Acetate, rayon, polyester

Who laid the foundations of blood and semen identification?

Mateu Orfila

Who should certify that the body is "dead"?

Medical examiner

If someone is beaten with a baseball bat, which type of spatter would you expect to occur?

Medium velocity

What is the SI unit for length?

Meter

What is a misdemeanor?

Minor Crime

If there is no nuclear DNA present, what type do scientists use?

Mitochondrial DNA

What is the most reliable and commonly used blood testing method that identifies the presence of agglutinogens in dried stains (antigens)?

Mixed agglutination

Small Particle Reagent (SPR)

Molybdenum Disulfide, solution of small black particles stick to fatty residues in fingerprint marks

Why not use blood for IA?

More complicated matrix due to interfering compounds such as proteins.

On a reversed-phase HPLC column, which compounds is likely to elute first? Heroin, Morphine, Codeine, Morphin-6-glucuronide, normorphine

Morphine-6-glucuronide

Three regions of IR Spectrum

Near IR= 12,500 to 4000cm^-1 Mid IR= 4000cm to 400cm^-1 Far IR =400 to 20cm^-1

You are using phenolphthalin to test a reddish-brown stain for the presence of blood. When you put a drop of phenolphthalin on the swab with your sample, it turns pink immediately. This test is:

Negative because it turned pink before the reaction was catalyzed.

Chemical methods for the development of latent fingerprints include

Ninhydrin, Diazafluoren (DFO), Sticky side powder, iodine fuming, cyanoacrylate fuming

Does crystallization occur when glass is cooled?

No

Number of minutiae to determine "match"

No overall standard

Does absorptivity in Beer's law have units?

No, the units cancel out

Bodily Excretion and Polarity

Normal bodily excretion of drugs becomes polarized by the liver so that it can be eliminated in urine When analysts are trying to extract drugs they want to get the drug to be non-polar so they can extract it into the organic solvent phase

What three fibers dissolve in formic acid?

Nylon, silk, acetate

Detectors (UV-Vis)

Often a photon transducer, create photocurrent through the absorption of radiation onto their photoemission surfaces

______ refers to when an instrument is tested and shown to meet previously set (frequently by the vendor) specifications. Performance Qualification, Installation Qualification, Operational Qualification, Design Qualification

Operational Qualification

What color is produced by Marquis' reagent in the presence of Amphetamine and Methamphetamine?

Orange

What color is produced by Dragendorffs reagent in the presence of alkalodial base, primary, secondary and tertiary amines?

Orange; Red-Orange; Brown-Orange precipitate

Non-polar drugs tend to be in which LLE phase?

Organic phase

The most common species determination test was developed by whom?

Ouchterlony

The fire triangle includes heat, fuel, and _____?

Oxygen

A vaginal swab that tests positive for acid phosphatase, but shows no spermatozoa on microscopic examination should be tested further for the presence of _____.

P30

Variation of headspace technique that uses a small strip of carbon fiber and the volatiles are extracted off of then injected.

Passive Headspace Diffusion (Charcoal Sampling)

Gamma Emitters require

Pb lined drawers and Pb bricks to place in front of the experiment, and Geiger counters

Resolution of two peaks is calculated from:

Peak width and retention time

Acetylating Agents for GC

Pentafluoropropionic anhydride (PFPA), and trifluoroacetic anhydride (TFAA), and acetic anhydride (AA), used for amines, amides, thiols, phenolic, alcohol and aromatic rings More stable than silyl derivatives

Pathology

Perform autopsies to determine death

Most common detector (UV-Vis)

Photomultiplier -made of several successive photoemissive dynodes -photos strike surface electrons are release -electrons strike remaining dynodes causing more electrons to be released -the cascade of electrons are accelerated to an anode for detection

Which cutting agents are NOT commonly used to cut heroin? Sugar, Brick dust, Plaster of Paris, Ground Vitamin Tablets

Plaster of Paris

What component of blood becomes activated when the circulatory system is breached and loss of blood occurs?

Platelets

Prior to the advent of DNA analysis, what did forensic serologists examine to help determine the origin of biological stains and fluids? mRNA, Saliva, Heterozygous Enzymes, Polymorphic Enzymes

Polymorphic Enzymes

Latent Print Evidence Categories

Porous and Non-porous

Criteria to be fulfilled to be diagnosis brainstem death

Preconditions, Exclusions and Tests

SDS ( Safety Data Sheets)

Product ID-name, synonyms, formula, MW and CAS #, Composition Info on ingredients Health hazards/first aid/personal protection Handling and Storage Flammability Physical and chemical properties Toxicology Disposal Methods Transportation Regulatory Other

Which male gland produces PSA?

Prostate

What color is produced by Dillie-Kopanyi reagent in the presence of Barbiturates?

Purple

What color is produced by Marquis' reagent in the presence of Opium Alkaloids?

Purple

3R rule

Radial cracks form a Right angle on the Reverse side of the force

Electromagnetic Spectrum

Radiation Type Frequency Wavelength Transition UV 10^15 - 10^17Hz 200-400nm outer electron Vis 4- 7.5 x 10^14Hz 400-800nm outer electron NearIR 10^12 - 10^14 Hz 1 um - 3 um molecular vibrations

the lowest to highest values of the data set and is a poor measure of precision.

Range

Optical Characteristics of Fibers

Refractive Index, Birefringence, Pleiochroism, Fluorescence, Heat Effects, Solubility Testing

Physical properties of glass to be examined:

Refractive Index, density determinations, elemental analysis

For short term storage, liquid blood samples should be kept:

Refrigerated

Beer's Law (Quiz)

Relates transmitted light intensity to concentration

The standard deviation divided by the average, times one hundred

Relative standard deviation or coefficient of variation

Specificity (Chromatographic)

Resolution of the analyte peak from any other compound verifies specificity which is shown in representative chromatograms

Chemical degradation

Result in loss of pure drug by breakdown to another compound

On which type of surface would you expect MORE spatter to occur?

Rough

Prep for External Inspections: Review of Operations

SOPS, sample prep, laboratory policies, employee records and training, logs of samples received, records of past issues, corrective actions, maitenance records, laboratory notebooks, validation records, variance letters from accreditation body that approve alt test methods, calibration records, COC

The most commonly used DNA analysis method today is ____.

STR

The "Christmas Tree Stain" is a confirmatory test for

Semen by finding sperm

What can fracture patterns tell an investigator?

Sequence of events Direction of impact High or low velocity impact

Fingerprint Classified By

Shapes and contours of individual patterns, noting the finger positions of the pattern types, relative size determined by counting the ridges in loops and tracing the ridges in whorls

Components of a Final Report

Should include: title page, abstract or summary, highlights, reserach plan, procedural changes, analysis of data, storage of records, signatures and dates, corrections and additions to the final report

For UV absorbance spectrophotometry, the sample cell is made of:

Silica

Common Stationary Phases for TLC

Silica gel, Cellulose, Ion Exchange Resins

Reagents used for Derivatization

Silylating and Acetylating

Three types of Scan Modes

Single Ion Monitoring (SIM), Selected Reaction Monitoring (SRM), and Multiple Reaction Monitoring (MRM)

Which one of the following is an example of wear evidence? The handle of the weapon touched by a perpetrator, Skin cells on the collar of a shirt worn by the perpetrator, both, none

Skins cells on the collar of a shirt worn by the perpetrator

Types of Glass

Soda-lime, borosilicate, and leaded

Which of the following is NOT an example of a smokeless powder (propellant)? Guncotton, Sodium Nitrate, Ballistite, Cordite N

Sodium Nitrate

Hemoglobin derivatives exhibit at strong absorbance at wavelength 400-425 nm. This is known as the:

Soret Band

What search pattern is typically used underwater? Strip/lane, grid, spiral, zig zag, quadrant

Spiral

What type of medullas do animals usually have?

Stacked, continuous or interrupted

The scatter of values around the average value.

Standard Deviation

Most Common Objective

Standard brightfield objectives

Direct examination would be the term applied to which of the following situations? State attorney asking the state witness a question State attorney asking the defendant a question The judge asking the state witness a question The judge asking the defendant a question

State attorney asking the state witness a question

Factors that affect reproducibility for TLC

Stationary Phase, Mobile Phase, Developing Tank, Temperature, Development Distance, Mass of Sample

Describe anthropometry.

Taking body measurements as a way to distinguish one individual from another

What is pH dependent on?

Temperature

Potential issue of cross-reactivity?

The concentration of the individual drugs may not be enough to trigger a positive confirmatory test, where the total concentration of the drugs gave a positive IA test.

If the refractive index of glass matches that of a liquid, what will you see when ou put the glass sample inside the liquid?

The glass will disappear

Limitations of SDS

The manufacturer is not required to perform exhaustive studies of health hazards and toxicology, etc. of every chemical sold but must report what is known about a compound The composition of some chemicals is sometimes considered proprietary knowledge. In the case of medical or other emergencies, the manufacturer should provide privileged info as to the ID of the compound to the appropriate medical personnel

Work place records

There are 3 types of work place records: Records--can document or facilitate the functioning of a lab and can include policicies, decisions, info mandated by federal or state law or by granting agencies, minutes of meeting and telephone logs Non-records--documents that do not further the understanding of the work in the laboratory or the program. They may be copies of an original record that is archived Personal Papers--papers concerned with an indiv. personal business ex. books or similar items purchased with personal funds

Double Beam Spectrophotometers

These have a mirror that splits the beam emerging from the monochromator. one of the beams passes through the reference solution to a detector and the second beam passes through the test sample to a matching detector. The two detector outputs are amplified and their ratio is determined electronically before being displayed.

Which of the following is NOT a hallucinogenic drug: marijuana, PCP, or LSD

They all are hallucinogenic

Most widely used technique for separation?

Thin Layer Chromatography

Elements of an SOP "in house"

Title of SOP, author, issue date, ID #, Page x of y, approval signature (senior lab official), some subsections include: Scope--elaborates on title Referenced Docs--source providing info for the SOP (federal standards, journal articles, SOP's of other labs) Defiinitions/Terminology--unfamiliar terms, common abbreviations Summary of Methods--briefly describes equip and general procedures Inferences--compounds that will interfere with results are noted Apparatus and Materials--lists devices, columns, detectors used in analysis, also should include syringes, bottles, vials Reagents--solvents, stock standards, reference standards, calibration standards, internal standards, surrogates, include conc. hazards, chemical grade, storage conditions Sample Collection, Preservation, and Handling--specific methods for handling a sample Procedures--Instrument or method calibration, sample prep and analysis, troubleshooting, calculations Quality Control--Procedures est. to demonstrate that instrument calibration, sample prep and analysis are preformed correctly. Method Performance--The min detectable level IMDL) of a substance in diff. matrices, % of recovered chemical Miscellaneous--flow charts, diagrams

What is identification used for?

To determine physical or chemical identity

What is comparison analysis used for?

To determine whether a common origin exists

What category of stain would a bloody shoeprint fall into?

Transfer stain

Catagen Phase

Transitional phase, 1-2 weeks long, hair follicle shrinks, lower part is destroyed and the dermal papilla breaks away

"Cutoff" is a term used in screening assays. (T/F)

True

A "cutoff" is the point below which all samples are considered to be negative. (T/F)

True

A competitive binding assay consists of placing a fixed quantity of the antibody in a tube together with a fixed quantity of labeled drug in addition to the drug sample to be assayed. (T/F)

True

A crystalline drug has a repeating arrangement of individual molecules (crystal lattice) and a characteristically narrow melting point range. (T/F)

True

A fingerprint residue that has been developed can be removed with a scalpel and DNA extracted if necessary (T/F)

True

A hapten is a small non-immunogenic molecule attached to a larger immunogenic substance forming a new antigen that stimulates production of antibodies specific for the small molecule. (T/F)

True

Adenine binds to thymine with two hydrogen bonds. (T/F)

True

All competitive immunoassay methods depend on the drug or analyte of interest being able to compete in the assay with an antibody and labeled drug. (T/F)

True

Amount of light passed through the cross polars depends on how close the analyzer is to parallel or crossed. (T/F)

True

An acid is a substance that can be charged or uncharged and is capable of donating a proton. (T/F)

True

Audits ensure that the laboratory is maintaining accreditation standards. (T/F)

True

Automotive undercoats and many architectural coatings with low luster finishes, container significant amounts of inorganic pigments which tend to have most of their infrared absorptions in the lower frequency of spectral region. (T/F)

True

Blood exhibits weak photoluminescence with excitation at 360 nm. (T/F)

True

CEDIA is a homogeneous assay with a long shelf life, but can be affected by urine adulterants, yielding false negative results. (T/F)

True

Chain of custody is required for any evidence submitted to court and can be used to establish the integrity of the evidence. (T/F)

True

Chemically unstable drugs are susceptible to hydrolysis, photolysis, and effects of temperature (T/F)

True

Chemicals with crystal lattice structures have narrow melting points. (T/F)

True

Color tests are generally rapid and simple. (T/F)

True

Color tests can be used on minimal amounts of sample. (T/F)

True

Color tests usually provide information on possible class or classes of drugs present in a test sample. (T/F)

True

Competitive immunoassays work on the principle of competition between an analyte present in the sample with a labeled drug or antibody specific for the drug of interest. (T/F)

True

Crystal violet is used on many types of adhesive tapes due to it only sticking to the latent prints. (T/F)

True

DFO develops 2.5 more latent print than Ninhydrin alone. (T/F)

True

DNA fragments are cut with restriction endonucleases during RFLP analysis.(T/F)

True

DNA is double stranded (T/F)

True

DNA segments are separate using gel electrophoresis during RFLP analysis. (T/F)

True

Deficiencies must be corrected in order to maintain accreditation. (T/F)

True

Different forms of electromagnetic light can induce chemical decay of chemically unstable compounds. (T/F)

True

During an audit the auditor may inspect many different types of records. (T/F)

True

During an audit the auditor may track a random specimen from time of collection to final result and report. (T/F)

True

During an audit the auditor may want to see how results are calculated. (T/F)

True

ELISA shows good sensitivity and is less prone to matrix effects, but the cost per sample is high. (T/F)

True

For ELISA a disadvantage is that cost per sample is high. (T/F)

True

For ELISA a disadvantage is that sodium azide will block action of horseradish peroxidase. (T/F)

True

For a pubic standard, the region needs to be combed before collecting the reference sample (T/F).

True

For quantitative immunoassays, multiple calibrators with concentrations that bracket those of the samples should be used. (T/F)

True

Gloves worn to protect latent prints are typically made of cotton. (T/F)

True

Heroin rapidly hydrolyzes in the body to become morphine (T/F)

True

Heroin vapors can be inhaled from off the aluminum foil and heated with a cigarette lighter and inhaled through a rolled-up dollar bill. (T/F)

True

Heterogeneous immunoassays require one or more wash steps to remove anything left unbound in the solution. (T/F)

True

Hydrolyzed body fat can help preserve a body and prevent putrefaction. (T/F)

True

Identification on the basis of the number of tests without reference to the discriminating power of the individual test is not warranted. (T/F)

True

If root sheath is present on the hair gender can be determine by looking for Barr bodies in the cells in the root sheath. (T/F)

True

Immunoassays have applications in postmortem and human performance investigations as well as in workplace drug testing. (T/F)

True

In CEDIA, the large recombinant protein fragment is the enzyme acceptor. (T/F)

True

In DNA electrophoresis, each DNA fragment carries a fluorescent tag on it's primer. (T/F)

True

In DNA electrophoresis, smaller DNA fragments move faster than larger DNA fragments. (T/F)

True

In DNA electrophoresis, the DNA fragments are separated according to size. (T/F)

True

In FPIA, fluorescein is very stable compared to drug enzyme conjugates, but fluorescent salts in bile often give false positive results. (T/F)

True

In Immunoassays, morphine is susceptible to cross-reactivity from thebaine, codeine, and dihydromorphine. (T/F)

True

In RIA, the amount of radiolabeled drug in the solution, or the amount bound to the antibody, is dependent on the amount of unlabeled drug present. (T/F)

True

In RIA, the analytical measurement is of radioactivity. (T/F)

True

In TLC, separation of drug mixtures is affected by drug solubility. (T/F)

True

In TLC, when the mobile phase is more polar than the stationary phase this is referred to as reversed-phase system. (T/F)

True

In an SOP there should be a section for referred documents, such as equipment manuals and other SOPs, as these documents are already present in the lab. (T/F)

True

In competitive immunoassay, the higher the concentration of the drug in the sample, the lower the concentration of labeled drug that will bind to the antibody. (T/F)

True

In immunoassays, Cannabinoids are susceptible to cross-reactivity from ibuprofen, naproxen, and ketoprofen. (T/F)

True

In immunoassays, LSD is susceptible to cross-reactivity from ergotamine, sertraline, and verapamil. (T/F)

True

In immunoassays, amphetamine and methamphetamine are susceptible to cross reactivity from MDA, MDMA, ephedrine, pseudoephedrine, fenfluramine, phenylpropanolamine, phentermine, phenmetrazine. (T/F)

True

In immunoassays, benzoylecgonine is susceptible to cross-reactivity from ecgonine, ecgonine methyl ester, and cocaine. (T/F)

True

In liquid-liquid extraction, a disadvantage is that emulsions may form trapping the drug. (T/F)

True

In the absence of a hair root, mitochondrial DNA testing may be carried out on the hair shaft. (T/F)

True

It is a detailed inspection of all aspects of the laboratory program. (T/F)

True

Laboratory examination of toolmarks is best carried out on the actual object. (T/F)

True

Larger the number the smaller the pellet (T/F)

True

Leucomalachite green can be used to stain bloody fingerprints to be photographed. (T/F)

True

Luminol is best used for locating the presence of hidden blood stains. (T/F)

True

Luminol is considered to be a presumptive test for blood. (T/F)

True

Luminol requires complete darkness for its use. (T/F)

True

Mature red blood cells do not contain DNA. (T/F)

True

Microscopy examination is the quickest, most accurate, and least destructive means of determining characteristics and polymer type of textile fibers. (T/F)

True

Mitochondrial DNA analysis may be conducted on hair shafts that contain no root materials. (T/F)

True

Mobile phase composition is dependent on the class/classes of drugs to be separated and the type of stationary phase chosen. (T/F)

True

Most fibers have a positive sign of elongation. (T/F)

True

Negative color tests can be used to rule out a drug. (T/F)

True

No absolute rule regarding what constitutes identification (T/F)

True

Once a sample is logged into a forensic laboratory there is a record that states when the sample was received and logged in. (T/F)

True

PD destroys DNA and may disintegrate any remaining residues. (T/F)

True

PGM can be found in blood, vaginal secretions, and semen? (T/F)

True

PLM can provide exclusionary feature between paint samples. (T/F)

True

Physical decomposition may involve changes in a drug's crystal lattice structure. (T/F)

True

Proton transfer can occur in solvents other than water. (T/F)

True

RFLP analysis requires the use of southern blotting. (T/F)

True

RIA does not require the use of a substrate. (T/F)

True

RIA is sensitive and resistant to matrix effects, but, as a heterogeneous assay, it is not easy to adapt to automation. (T/F)

True

Red Cell Ag = A and B + Serum Ab = None -> ABO type is AB

True

Red cell Ag = B + Serum Ab = A -> ABO type is B (T/F)

True

Red cell Ag = None + Serum Ab = A and B -> ABO type is O

True

Steel and fountain pens do produce identifying characteristics with time allowing writing to be traced back to a specific pen. (T/F)

True

Substitutions on the nitrogen and ring system of amphetamine give you analogs. (T/F)

True

TLC allows several samples to be run simultaneously. (T/F)

True

TLC can be used to separate mixtures of drugs. (T/F)

True

TLC offers lower sensitivity and resolution than gas chromatography methods. (T/F)

True

Test toolmarks must be made in a way that duplicate the way the question mark was made. (T/F)

True

The acidity of any acid depends on the basicity of the base that accepts the proton. (T/F)

True

The amylase activity in saliva is variable from person to person often resulting in inconclusive testing for its presence. (T/F)

True

The common elements of an immunoassay reaction are: antigen, antibody, molecular label and a substrate molecule. (T/F)

True

The image in the eye is a virtual image. (T/F)

True

The relative strength of an acid or base depends on the environment of the acid or base. (T/F)

True

The shape of a molecule will affect its mobility. (T/F)

True

The surface tension of blood is less than that of water. (T/F)

True

There is wide variance throughout a sample and even throughout a single hair. (T/F)

True

To conduct color tests, a technician requires little training. (T/F)

True

Traces of impurities in street drugs may cause misleading results or interfere with crystal formation, making identification difficult. (T/F)

True

Video recording is an acceptable method of recording a crime scene. (T/F)

True

When at the crime scene, a overview, a general shot with features to identify the location should be recorded via photography. (T/F)

True

When at the crime scene, the evidence detail, perhaps with close-up procedures should be recorded via photography. (T/F)

True

When at the crime scene, the location of any significant evidence, usually a mid-range shot should be recorded via photography. (T/F)

True

When inflicting a deep stab wound, the body tissue may "wipe" blood off the weapon as it is withdrawn from the wound. (T/F)

True

When searching for the origin of a fire; fire requires fuel and oxygen to continue burning. (T/F)

True

When the stationary phase is more polar than the mobile phase this is referred to as a normal phase system. (T/F)

True

When using an alternative light source to search for biological fluids, the wavelength of light used must be opposite to that of the color of the stain. (T/F)

True

pH is affected by temperature. (T/F)

True

pH is an important factor in the extraction and analysis of drugs. (T/F)

True

pH is an important parameter in the absorption, distribution and excretion of drugs. (T/F)

True

pH is the measure of the acidity or basicity of a solution. (T/F)

True

Hairs for standard should not be cut. (T/F)

True (for UF test)

Factors that affect Quality Assurance and Quality Control

Turn-around time, quality and price Depends on the industry as to which is more important For food industry it's turn around time ex. produce industry works on positive release basis (results prior to distribution) There are situations when both are needed and this is a challenge ex. gov. commissioned food safety and quality monitoring programs Price is the rate offered to the customer. Loss leaders are when a item or service is sold below cost to attract customers

Which type of uncertainty can be gathered from historical laboratory data, that is, a large number of repeated measurements taken of the analyte over a period of time? Type A or Type B

Type A

Inferential Statistics (inductive statistics)

Type of statistics where probability theory is utilized to determine if results are significant, clinical studies are prone to this bc there are so many variables associated with humans (such as--genetics, life style and exercise, environment, medications, indiv. not following protocol), control groups are utilized to make comparisons when there are less than 30 samples (n< 30) the distribution is less likely to be normal Student's t-distribution can be used to deter the confidence interval for both small and large populations, best when examining paired averages--where one wants to know whether the avg values are diff for a specific parameter obtained by two diff methods Duncan's Separation of Means Procedure--way to statistically deter whether more than two averages are statistically different CHi-square test--used to deter whether two groups of data are different, measures diff bt observed and theoretical frequencies of an event occurring

Major Fingerprint Characteristics

Typelines, delta, cores

The fundamental mechanisms considered necessary to maintain the BBP standard and are the primary mechanisms for infection control.

Universal precautions

Lab Receipt of Sample

Upon receipt of a lab sample the laboratory should: verify the integrity and condition of the sample ctgrs, verify documentation (ID #s match, all samples present), verify storage temp

Matrix of choice for IA

Urine, because it has fewer interfering compounds and decomposition products

The measurement of the dispersion of values is the square of the standard deviation and is considered the best measure of precision.

Variance

What color is produced by Ehrlich's reagent in the presence of Hallucinogens?

Violet

What color is produced by Duquenois-Levine reagent in the presence of marijuana/THC?

Violet-Blue can be extracted into chloroform

Porous surface recommend sequence:

Visual examination, examination with light source, iodine fuming, magnetic powders, DFO/Ninhydrin, physical developer

Which is not a DNA quantitation technique? Slot blot, Western blot, Real-time PCR, Picogreen Assay

Western Blot

Would you expect a blood stain resulting from a 90 degree angle to be WIDER or THINNER than that from a drop coming at 50 degrees?

Wider

In regards to paint analysis, which of the following methods is usually not suitable for the identification of organic pigments?

X-ray Diffraction (XRD)

Can scientists determine body area that hair came from comparison?

Yes

Is it possible to sequence points of impact on a glass pane?

Yes

What is not a typical search pattern? Strip or lane search, grid search, spiral search, zig zag search, quadrant search

Zig Zag search

What separates the outer root sheath and the dermal sheath?

a basement membrane

A swipe bloodstain pattern is the result of

a bloody object in motion contacting another clean surface

Button Method

a carbide plug with a rifled cross section is pushed/pulled through the bore

Forensic Court reports covered by FBI Quality assurance standards for Forensic DNA Testing Labs should include

a case identifier, description of the evidence examined, a description of methodology, the locus used, results/conclusions, interpretive statement, date issued, disposition of evidence, a signature and title in addition, ISO17025 requires that: total # of pages on any hard copies of the report, the name and address of the client, unique ID # on report, descrip of the sampling plan, date of receipt of test item

Calibration (Definition)

a comparison of measurement, standard, instrument, or item with a standard instrument of higher accuracy to detect and quantify inaccuracies and to report or eliminate those in inaccuracies by making adjustments. (physical measurements vs. acceptable standards)

The velocity of light in a vacuum is:

a constant

Isocratic separation is on that is achieved using:

a constant solvent composition

Hook Method

a cutter is pulled from end to end repeatedly until the desired depth is achieved

Antigens

a foreign body, molecules that elicit an immune response and bind with antibodies

Manufacturing of Laminated glass

a laminated sheet of transparent polyvinyl butyral plastic between two sheets of thin plate glass

Hammer Method

a mandrel with a rifling configuration is forced into the bore by external hammering

If the paint smear is on a metal or high reflective substrate then it may be possible to obtain:

a reflection-absorption spectrum of the smear using the reflectance mode

High Performance Liquid Chromatography (HPLC)

a sample is injected onto the column through an injection port using a syringe. individual components are separated on the column are detected as they emerge by a detector.

Auxochrome

a saturated chemical group that has little to no absorption but modifies the absorption spectrum when attached to a chromophore

Broach Method

a series of progressively larger cutters for the rifling with a single pass

Single Beam Spectrophotometers

a single light source pass through a test sample to a single detector

Positive control

a substance that is known to react in the expected way of the test being performed, ex. if testing urine for amphetamines, using a positive control that is spiked with amphetamines in the std

Standard Operating Procedure (SOP) defined

a written document that details the method for an operation, analysis, or action with thoroughly prescribed techniques and steps that is officially approved as the method for performing certain routine or repetitive tasks

Sampling of Drug Evidence

acceptable to analyze 10% of the total number of packages

Classes of Synthetic Fibers:

acetate, acrylic, aramid, nylon, polyester, and rayon

Psilocybin

active substance found in Psilocybe, Conobybe, Paneolis, and Stropharia mushrooms

Degasser

added to HPLC to remove air from the mobile phase

Lifting

adhesive tape is repeatedly and firmly patted or rolled over an item to pick up loose trace evidence, then placed on transparent sheet to protect against contamination and allow easy viewing of samples

HPLC Separation Modes

adsorption/normal phase reversed-phase ion exchange size exclusion

The change in body temperature post mortem is called ...

algor mortis

Groups that do NOT significantly ionize in water

alkanes, alkenes, alkynes, ketones, amides, ethers

Documentation and Record Storage

all documentation generated from the validation process, stored in an organized manner and in the correct format and location

Inspection

all items used in an analysis must be inspected, equipment qualification is a type of inspection, equipment and consumables must be examined after purchase, identities of items should be verified and documented, other forms included would be performance qualification, calibration, and tuning procedures, inspect glassware for cleanliness and cracks

Laboratory Ventilation

all lab areas replace the air in the room with air that is non-laboratory air at 4-12 air changes per hour with air intake NOT being near the air exhaust. The quality and quantity of air ventilation should be analyzed every 3mos

Edmund Locard (1920-1929)

almost impossible for anyone to participate in any activity without removing soil or dust particles from the site by contaminating their person or vehicle

Natural variation in a person's handwriting is ___ when compared to the variation between individuals

always less

No conclusion -firearms

ammunition components could not be identified or eliminated as having been fired by a particular weapon based on the quantity and quality of microscopic marking class characteristics in agreement but individual characteristics are insufficient or absent

Examples of Drugs that are acids

amobarbital, aspirin, ibuprofen, penicillins, warfarin

Angle of Incidence (ATR-FTIR)

amount of radiation that is reflected and determines depth of penetration

Retention

amount of time spent in the stationary phase versus the mobile phase

Drugs derivatized by Acetylating Agents

amphetamine, MDMA, and methylphenidate

The cocaine metabolite benzoylecgonine is:

amphoteric

Indented writings on evidence can be visualized with an instrument called

an Electrostatic Detection Apparatus (ESDA)

A flammable liquid that was used to start a fire is called

an accelerant

Homogeneity of Solutions

an aliquot should be taken from the top, middle, and bottom of the sample containing each sample is analyzed in triple replicate, concentration should fall into previously determined the acceptable range for a sample to be considered homogeneous

Glass

an amorphous substance composed of silicon oxides and metal oxides, borates or phosphates fused at high temperature.

What is the role of isoamyl alcohol in organic DNA extraction methods?

an anti-foaming agent

Nuclear blast

an event where somatic and cellular death occur simultaneously

Examples of schedule III

anabolic steroids, codeine, hydrocodone with aspirin or acetaminophen

What are the three phases of hair growth?

anagen, catagen, telogen

Narcotic drugs are

analgesics

Screen

analysis that is employed to ID/separate various classes of analytes within a sample ex. drinking water using GC/MS

The ACE-V method of print identification involves

analysis, comparison, evaluation, and verification

Elution of Sample

analyte of interest is eluted from the column and collected in a tube using a suitable solvent

The following parameters are not used in the identification of drug microcrystals.

angle of extension

The following parameters are used in identification of drug microcrystals.

angle of extinction, sign of elongation, refractive index, and sing of absorbance

Preventive Maintenance (PM)

anticipates problems that cannot be prevented with routine maintenance ex. replacing oil, cleaning internal parts, replacing worn parts

Monoclonal Antibodies

antigen immunization process however specific antibody producing cells are removed from the animal's spleen or lymph nodes and the antibodies are produced in vitro through a tissue culture

Forensic Science

application of nature science principles and technology to the legal process

Why are Preliminary / Screening Tests used?

applied to determine number of possible substances present in an unknown sample

Electrostatic Detection Apparatus (ESDA)

applying an electrostatic field can make the modifications to the properties of the surface apparent

Sir Edward Richard Henry

appointed head of Scotland Yard implemented his fingerprint classification scheme (Henry System) which eventually replaced anthropometry

Stress/fracture marks

arch shaped striations on the fragment edge, beginning at right angles to the surface from which the crack originated and curve nearly parallel to the opposite surface (where the applied force is from)

The basic fingerprint class patterns are:

arches, loops, and whorls

Hypsochromic Shift

aromatic amines in a acidic environment causes the protonated quaternary group to no longer be part of the chromophore shifting the spectrum to shorter (lower) wavelength

Solvent effects in UV-Vis

aromatic chromophores show fine vibrational in non-polar solvents due to solute-solvent interactions. In aqueous solutions, the pH affects ionizable chromophores due to conjugation changes in the ionized and non-ionized chromophore

Elements to detect in elemental analysis of glass

arsenic, cobalt, titanium, sulfur, lead, boron, zirconium, strontium, barium, iron, and chromium

Automated Fingerprint Identification System (AFIS)

as a means of providing identification services to US law enforcement communities

Inorganic Fibers

asbestos and glass fibers

Ruggedness

assess what effect changing factors external to the method might have example method used ina another lab, by another instrument or other analysts

Robustness

assess what effect changing method conditions might have on the results and acceptance criteria example: adjust pH of buffer in sample prep or in LC mobile phase

Use for distance determination

assessing whether or not the crime was suicide or not

Death

at the point at which the heart stopped beating and breathing ceased

Examples of drugs that are bases

atropine, codeine, epinephrine, streptomycin, cocaine

Collected writing samples should be

authenticated and from an appropriate time period.

Common Descriptive Statistics

average (or mean), median, mode (appears most often), confidence interval (how confident one is that results are accurate), measures of precision (range, standard deviation (scatter of values around the avg value) , variance (best measure of precision), relative std deviation or coefficient of variation, graphical representations, calibration curves

Going from high RI to low RI the light is bent:

away from normal

Final Report: Research Plan

background info and study objectives are included along with experimental design and methods. FDA and EPA require--description of test articles, description of test system, description of methods used

Writing instruments include

ball point pens, fountain pens, fiber tip pens, pencil

Drugs/Drug Class that have good UV Absorbance

barbituates (phenobarbital), benzodiazepines (diazepam), phenothiazines, tricyclic antidepressants, psilocin, cocaine, heroin, LSD, Methamphetamine, MDMA

Primer Mixtures contain elements:

barium and antimony

Components of a firearm

barrel, firing chamber, stock and action

Protective measures to avoid direct contact with potentially infectious materials:

barrier protection, appropriate eye and face protection, place contaminated sharps in closable, leak proof, puncture-resistant containers, prohibit eating, drinking or applying cosmetics, wash hands after removing gloves or other PPE, well-fitting respirators

Amphetamines

base for other analogs such as: methamphetamine, methylene dioxymethamphetamine (MDMA)/Ecstasy.

Ion Exchange

based on the affinity the sample's ion s have for the ionic group that the analyte can bind to

Immunoassays

based on the formation of an antigen-antibody complex with the addition of some form of label that will ultimately be the source for detection and measurement of antigens contained in the samples being analyzed.

Locard's Exchange Principle

basic tenet of forensic science "every contact leaves a trace"

Condition of a Sample Description

be sure to include features and appearances of the substance that will be tested such as: --weight (dry or wet) --amount if in tablet form --# of packages --nature of substance --Color --odor --condition (wet or dry)

Fiber Color

be uniform or it can vary

At what point can a corpse be fingerprinted?

before or after the onset of rigor mortis or after the start of decomposition

Cotton's characteristic microscopic feature

being a flat spiral shape

Where is the analyzer placed?

between the objective rear aperture and the observation tubes/camera port

Examples of minutiae

bifurcation, ridge ending, island, etc

IR and FTIR can obtain information on what is in paint?

binders, pigments, and additives

Raman Spectroscopy can also be used to obtain what information about paint:

binders, pigments, and additives same as FTIR

Which is NOT a variable to consider when examining blood patterns?

blood alcohol level when blood is shed

Evidence from Heroin syringes

blood from user

When is de-gloving technique used?

bodies that have been immersed in a body of water or are in a more advanced state of decomposition

Borosilicate glass ingredients:

borax, silica and alkali

Soda-lime glass is used to make...

bottles, tableware, lamp bulbs, and window and plate glass

Conditions of PVS

brainstem remains functional, patient breathes unaided and certain reflexes are observed, show no behavioral evidence of awareness, do not speak or initiate purposeful limb movements, higher brain function are absent

Cartridge Cases

brass or nickel-plated brass or aluminum or plastic

Properties of tempered glass

breaks into small fragments, typically cube like rather than sharp splinters

European Ancestry "Caucasian"

broad range of color, pigment densities and shades, oval cross-sectional shape, curl and range of diameter is between negroid and mongoloid ancestry

Projectile

bullet

Microscopical Examination Firearms

bullets and cartridge cases from test fires are compared to suspect evidence by comparison microscopy

Substrate samples collected from the scene of a suspicious fire should be taken from

burned and unburned areas

When would rehydration of hands be beneifical?

burned or charred bodies

How is glass colored?

by adding metallic oxides, sulfides, or selenides or microscopic particles

Specificity of assay when impurity or degradation product standards are unavailable

by comparing the test results of samples containing impurities or degradation products to a second validated method. This should include samples stored under relevant conditions of heat, light, humidity, acid/base hydrolysis, oxidation

Determine Accuracy

by comparison of the results of the proposed analytical procedure with those of a second well-characterized procedure. should be done using at least 9 determinations with three concentration levels. Generally reported as the difference between the mean and the accepted true value together with the confidence intervals.

How to Secure the scene?

by setting up physical barriers to prevent unwanted person from entering the perimeter

Class characteristics of a firearm detectable from a fired bullet include

caliber, lands/grooves, and rifling (direction and degree)

Class Characteristics of Bullet

caliber, number of lands and grooves, direction of rifling, groove width

Fingerprint powder brushes are made of?

camelhair, squirrel hair and fiberglass

Comparison of known and question paint samples

can be made under stereomicroscope, noting difference in color, pigment appearance, surface details, inclusions, metallic and pearlescent flake size and distribution and layer defects

Study Protocol

can refer to: a prelimiary memo by diplomatic negotiators as a basis for a final treaty ex. ozone layer, the formatting and treatment of data in an electronic communication system, a strict code concerning proper etiquette and rules of precedence, a detailed plan of scientific or medical procedures for QA/QC work, a study protocol is a document that lays out the objectives and a detailed description of the total experiment or research activity.

Active Components of Marijuana

cannabinoids

Special Classes of Hazardous Waste

carcinogens, teratogens and mutagens, compressed gasses, radioactive materials, cryogenic materials

Ammunition

cartridge case with propellant, primer, and bullet

Solid Phase Extraction (SPE)

cartridges consist of a polyproylene tube with a stationary phase of bonded silica sorbent material held in place by an upper and lower frit and a mobile liquid phase.

Charles Waite

catalogued information regarding weapon manufacture

What does rifling do?

causes the projectile to spin as it travels down the barrel enabling it to fly straighter which improves accuracy

Barr Bodies

cellular structure associated with the nuclei of female cells, not a fool-proof method of gender determination

Central stockroom

central to all laboratories makes everything more efficient and cost-effective than having separate stock rooms

Physical decomposition

changes in crystal form of drug, aggregation of drug particles in a suspension, loss of volatile chemical compounds to the atmosphere and container

Presumptive Test Advantages

cheap, no expensive equipment needed, minimal training, and minimal sample

Drug compounds that are not chemically stable may be susceptible to:

chemical, microbial and physical degradation

Drugs with Natural Fluorescence

chlorquine, dantroline, lysergic acid diethylamide (LSD), propranolol, quinidine

Color of fingerprint powder

chosen to contrast with the object to be photograph, should also keep in mind what color the backing card is

Combing

clean comb/brush used to recover trace evidence from the hair of an individual , comb and debris packaged together

4th and final layer of paint

clearcoat

Clipping

clipping of fingernails, package right and left hands separately

Definition of Accuracy

closeness of agreement between a measured quantity value and a true quantity value of a measurand combination of systematic and random errors

Define Precision (Reproducibility)

closeness of agreement between replicate measurements taken in different laboratories by different personnel using different instrumentation

Standard Ammunition File (SAF)

collection of over 15,000 military and commercial ammunition specimens of foreign and domestic manufacture

Morphological Components to look for by Microscopy

color, diameter range, degree of twist or curl, pigment granule distribution, and size or shape of granules

Features used in hair examination:

color, length, diameter, pigment granules (distribution, shape, and color), medulla

Chromophore

color-producing molecular groups responsible for energy absorption

Exclusions for Brainstem Death

coma caused by the following: intoxication by drink or drugs, hypothermia, metabolic or endocrine disturbance

Questioned Documents Examination

comparison and interpretation of handwriting, materials generated from typing, printing, fascimiles, and photocopying and the analysis and aging of paper, inks, and materials used to produce documents

One of the best techniques to discriminate between fibers is:

comparison microscopy

Sign of Elongation

comparison of RIs in the fiber, n(parallel) and n(perpendicular)

Advantages of Double Beam Spectrophotometers

compensation for the fluctuations in output of the source compensation for variations in source intensity and wavelength continuously recording absorbance and transmittance data

What are common components and/or features of a drug immunoassay?

competitive binding, labeled drug, antibodies and antigens.

Refractive Indices of a material are dependent on:

composition and on particular directions within the crystal

Electron signals on SEM-EDS produce

composition and topographical information about a sample

Extraction Efficiency

concentration extraction of the sample divided by the concentration of the sample spiked

Confirmation bias

concept of accepting conclusions of another withou due diligence of the scientific process

Three physical characters to identify glass

conchoidal fracture, amorphous structure and isotropism

What are the sequential steps of solid phase drug extraction?

condition, change pH environment, sample application, rinse, elution

Interference Studies

conducted to alleviate the potential for incorrect evaluation of the analyte of interest

James Marsh

considered to be the first to provide toxicological evidence supporting arsenic detection for a legal trial

Schedule II

considered to have high potential for abuse that may lead to severe psychological or physical dependence, do currently have accepted medical use in the US or accepted with severe restrictions

Lambert's Law

considers instrument factors, states that for a given concentration (C) the radiation transmitted through a homogeneously absorbing system (I) decreases exponentially with increasing path length (b)

Beer's Law

considers sample concentration for a given path length (b) the transmitted intensity (I) decreases exponentially with an increasing sample concentration (c) of a homogeneously absorbing system.

Dermal papilla

consists of a highly active group of cells responsible for hair production

Handwriting comparisons can be made using

construction of letters, where pressure is applied, and connections between letters

Toolmarks

contact between a tool and some other surface

Properties of Ion Exchange Resins (TLC)

containing quaternary ammonium or sulfonic acid groups for ion exchange bonded to surface of the plate, good for high MW substances and amphoteric compounds, mobile phase is usually a strong acid or base

Biohazards Hoods

containment and protection of samples and operator

Firing Chamber

contains the cartridge when it is fired

Fiberglass

continuous and non-continuous

Environmental Protection Agency (EPA)

control of hazardous waste from "cradle-to-grave" from the Resource Conservation Recovery Act (RCRA) of 1976

Analytical Information Management System (AIMS)

converts data from standard format, search data archives and serves as a central repository for all instrumental data

Uses of borosilicate glass:

cooking utensils, laboratory glassware and chemical process equipment

Common coating on lead bullets

copper or brass

Most common natural fiber

cotton

Disadvantages of pulsed-spitless Injection

could overwhelm the inlet and cause flashback contaminating the gas supply lines and septum

Casts of Toolmark impressions

create a clay dam around the toolmark and pour an eposy or plastic casting material into the isolated region or by using putties

American Society for Testing and Materials (ASTM)

created with the purpose of standardizing methods and terminology unique to the field

Cuticle scale patterns can be obtained by:

creating casts of the hair in nail polish and then removing the hair from the nail polish and observing the cast left in the nail polish

Physical features of synthetic fibers to look at:

crimp, length, color, relative diameter, luster, apparent cross section, damage, adhering debris

Broke waste glass is called:

cullet

The outer layer of hair is:

cuticle

What are the three layers of the inner root sheath?

cuticle, Huxley layer and Henle layer

Causes of Interference (Drug Analyze)

cutting agents, impurities, by-products, precursors

Revolver

cylinder that holds several firing chambers and rotates to bring each chamber in line with the barrel of the gun

Hash Oil

dark brown/black liquid produced by extracting marijuana with a solvent and concentrating the extract, few drops added to tobacco and smoked

Drugfire and National Integrated Balistics Information Network (NIBIN)

database to compare and link evidence obtain in serial shooting investigations

Cellular Death

death of each and every individual component

Contamination and Transfer

decontaminate equipment after use to prevent subsequent transfer and infection

African Ancestry "Negroid" (Black) Hairs

deeply pigmented, different shade of color, coarse clustering of pigment granules, tightly curled due to flattened elliptical cross sections

Chain of Custody

defined as an unbroken trail of accountability that ensures the physical security of samples, data and records, signature or initials of each individual receiving or transferring the evidence should be recorded with an identifier #, should include the date and quanity of the batch Prevents 2 common methods by which analytical results can be challenged: 1. showing that the analytical procedure was not accurate 2. raising doubt about whether or not this was the correct sample Legally defendable when it can be shown that the original sample could not have been exchanged for other sample

What parameters affect how well an analyte extracts into an organic solvent?

degree of ionization, pH of drug environment, and pKa of the drug

Pump (HPLC)

delivers mobile phase to the column at a controlled rate and elevated pressure

Quantum FTIR Detectors

depend on the interactions of raidation with electrons in a solid causing electrons to be excited to a higher energy state mercury cadmium tellurium (MCT)

Partition Coefficient (K)

dependent on the nature of the drug and the organic solvent, temperature, and degree of ionization

Alcohol is an example of a

depressant

LSD

derivative of ergot alkaloid, lysergic acid is found in the Claviceps purpurea fungus which infects grains semi-synthetic compound, typically taken orally, should as blotters or sugar cubes with each hit containing around 100 micrograms

What is at the base of each active hair follicle?

dermal papilla

Solubility Testing

destructive method, provide supplemental information, fiber reactions: partial and complete solubility, swelling, shrinking, gelling and color change

Pyrolysis Gas Chromatography (PGC) in Paint Analysis

destructive technique, can identify binder type and enabling discrimination of chemically similar paints

PGC-MS in Paint Analysis

detection of binder components, reconstructed total ion chromatogram may have information about additives, organic pigments, and impurities

2nd step of hair examination

determine if human or animal

Waite, Goddard, Gravelle, and Fisher

developed comparison microscopy for bullet comparison

August Vollmer

developed the First United States police crime laboratory of the Los Angeles County Sheriffs department

Franz Josef Holzer

developed the absorption-inhibition ABO typing technique

Alphonse Bertillon (1879)

developed the most significant and earliest personal identification anthropometric system based on the measurements of the body known as Bertillonage

Sir Alex Jeffreys

developed the techniques for profile analysis of DNA called to apply DNA testing to a criminal investigation for the first time

Latent prints on paper products should be ....

developed with chemicals

TapeGlo Fluorescent Dye

developing latent prints on the adhesive side of tape, laser light is used to visualize

Culliford and Wraxal

development of electrophoretic techniques for haptoglobin typing and isoenzyme due to the determination of the polymorphic nature of erythrocyte acid phosphatase (EAP), phosphoglucomutase (PGM) and adenylate cyclase (AK)

OSHA Act of 1970

development of enforceable, mandatory job safety standards to reduce work place hazards the establishment of responsibilities and rights for employers and employees to achieve better safety and health condition, and implement of a record keeping system to monitor and report job-related injuries and illnesses

Pleiochroism

differential absorption of light by an object when viewed at different orientations relative to the vibration direction of the plane polarized light

Prep for External Inspections: Laboratory Clean-up

discard expired chemicals and stock soltns, remove equip and chemicals that are not used, est that equip and instruments needed are available, check equip files to be sure they are all up to date, check for labels on instruments (ID#, install date, date of last maitenance, etc), check that all bottles are labeled, place samples analyzed, reagent bottles in their proper locations, discard samples and records no longer needed

Hugo Marx

dissertation on the value of forensic hair examination after a textbook published that had a chapter on investigation of hair

Primary Classification

divide all fingerprints into 1024 groups, can narrow a search but cannot identify an individual

The Lafarge Case

documented as the first case in which the defense called an opposing expert

Gunshot residue:

does not travel a great distance

Properties of Wire glass

doesn't shatter if it is struck

Derivatization for GC

done to alleviate volatility and stability issue and improve chromatography

Common fingerprint minutiae include

dots, bifurcations, islands

Hashish

dried resin from the fruiting and flowering tops of the cannabis plant, pressed into slabs and crumbled and mixed with tobacco and smoked

Marijuana is used

dried, crushed, mixed with tobacco and smoked in a reefer or a pipe

TLC Principle

drug separation is achieved through interactions between the drug and the surface of stationary phase particles either through a combination of adsorption and partitioning between phases.

PD surfaces to be used on:

dry paper, bricks, masonry, latex gloves, both sides of adhesive tape, wet or previously wet paper, rayon, nylon clothing, porcelain, unfinished wood, and items not touched in years

Borosilicate glass properties:

durable, resistant to chemicals, and high temperature

Cortical/matrix epidermal cell

during growth phase they divide and proliferate rapidly

Water Usage in Laboratories

each lab must have at least one sink for washing hands each lab should have an eyewash station each lab should have a safety shower with a drain under the shower to aid in clean-up plumbing should be made of acid-resistant materials DNA analysis requires pure water and deionized for post amplified

Forensic Medicine

earliest documented forensic specialty, now considered a separate discipline to forensic science

Indented or Plastic Prints

easily seen embedded in a soft surface, putty, plaster, etc. 3D nature may be difficult to see or photograph without specialized lighting. May be possible to powder or cast the print

Patent prints

easily seen prints

Extraction Recovery

efficiency of the extraction procedure, same concentration in appropriate matrix, extracted and injected into the system, repeated at least 3 times at 3 different concentrations.

Types of light scatting

elastic and inelastic

Raleigh Scattering

elastic scattering, no change in energy, the resultant frequency of scattered light is the same as the incident light frequency

1st Layer of Paint

electrocoat primer (e-coat)

Disadvantages of UV-Vis Detector

eluent may absorb at optimum detection wavelength only compounds with chromophores can be detected relatively poor sensitivity

UV-Vis Detector

eluent passes through flow cells while being radiated by UV light, sample absorbs UV light, sensor detects that change

Varying the pH of the mobile phase will help with...

elution order/retention of the analytes can be adjusted to help with separation

Fluroescence

emission of light of a certain wavelength by an object when excited by light of a shorter wavelength

Stokes scattering

emitted photons end up at a higher vibrational energy state or wavelength then the original

How does XRD works?

employs a copper target X-ray tube to generate the x-ray beam and a diffractometer to measure the diffraction angles and peak intensities characteristic of the crystal structure

Disadvantages of Liquid-Liquid Extraction

emulsions may form trapping the drug, immiscible solvents are required, time consuming, glassware clean-up, large volumes of solvents used, skill involved by operator

Concentric fractures

encircle the site of penetration, they form second, and start on the impact side

Total Ion Chromatogram (TIC)

entire range of masses is scanned, base peak is given 100% relative abundance and the rest are proprotional

De-gloving

epidermis and dermis of the decedent's fingers are removed and placed on top of a gloved finger to attempt to create an inked or powdered print

Three layers of the skin

epidermis, dermis and hypodermis

Primer

epoxy modified polyester, colored according to the color of the top coat

Electrocoat primer

epoxy resin applied by electroplating directly to the steel, usually gray to black in color

Juan Vucetich

established his own fingerprint classification system based on his own research and fingerprint pattern types described by Francis Galton

FBI Crime Lab

established in 1932

Which is the most abused drug on the world

ethanol

Carry Over

evaluated to see if previously analyzed sample's analytes might elute on subsequent instrumental runs

1st step of Fingerprint Detection

examine all surfaces and objects

Phase Contrast

excellent method of improving contrast in unstained biological specimens without significant loss in resolution

Amphoteric compounds

exhibit both properties of acids and bases, optimal extraction of these chemicals can only be achieved by adjusting the pH to get the drug into an unionized form. Ex. morphine, pH = 8

Chemical reactions that give off heat are called:

exothermic reactions

Disadvantages of RIA

exposure to radiation and waste disposal requirements

How to examine pipes for cannabis residue?

extract cannabinoids using petroleum ether and then run on GC-MS

Washing of the column

extraneous compounds in the sample matrix are washed out of the column by using a suitable solvent. Then the sorbent bed is dried

Advantages of Vacuum Metal Deposition

extremely sensitive on a variety of surfaces, can be employed in conjunction with cyanoacrylate fuming

Fingerprints change over the course of a person's lifetime (T/F)

false

Most reconstruction patterns are easily transported to the lab for further analysis (T/F)

false

you should only document what you see

false

The synthetic opiate that was unknowingly injected by drug users and caused near-instant death was ...

fentanyl

Disadvantages to Fluorescence Spectrophotometry

few drugs have native fluorescence unable to distinguish between parent drug and metabolite

Three Categories of Glass Fibers

fiberglass, mineral wool, refractory ceramic fibers

Immersion technique of determining refractive index

finding the temperature and wavelength at which the glass fragment in a liquid has the same RI as that liquid

Live Scanning

finger and palm prints to be submitted electronically, pressure changes can have similar effects to using too much ink

Vacuum Metal Deposition

fingerprint contamination hinders the deposition of a metallic film following evaporation under vacuum

1500-200cm^-1

fingerprint region, spectral "fingerprint" can be used to assist in identifying a drug

X-ray Detection

fingerprints dusted with lead powder and then x-rayed

Class Characteristics from Cartridge case

firing pin strike, breechface impressions, ejector striations, chamber marks

Leone Lattes

first developed antibody tests for the ABO blood groups

Rudolph Virchow

first forensic investigation of human hair

Functions of the skin

first line of defense, inhibits excessive fluid loss, controls body temperature

Dr George Popp

first recorded use of botanical evidence in a criminal case

Dr Alexandre Lacassagne

first to associate bullets with a specific gun, first to study blood spatter patterns

Hirschfield

first to identify the polymorphic nature of group specific component (GC)

Francis Galton

first to publish a systematic identification of fingerprints, devised the first scientific methods for the classification of fingerprint patterns

Alphonse Bertillon

first to use systematic crime scene photography for recording a scene

Henry Goddard

first used bullet comparsions

The lowest temperature at which a liquid fuel produces a flammable vapour

flash point

The linear relationship between concentration and absorbance, as represented by Beer's Law, can be affected by:

fluorescence of the sample, non-monochromatic light, particulates in the sample, electrostatic interactions between molecules

Forensic Toxicology

focuses on the identification and quantitation of toxic substances in body fluids and tissues and the subsequent determination of the role any such agent may have played in contributing to or causing death

Advantages of Pulsed-spitless Injection

for more volatile compounds so they don't get lost to the split vent also useful for thermally labile sample components

During visually inspection how are fibers collected?

forceps

Gas Chromatography (GC)

form of partition chromatography utilizing a gas mobile phase and liquid stationary phase attached to a fused-silica column, compounds that prefer the stationary phase will have a longer retention time than one that prefers the gas mobile phase

Non-porous Disadvantages

fragile because residue just lies on the surface, slightest handling can wipe away the print

Types of medullas

fragmented, interrupted, continuous, absent

What is the hardest prints to get?

from a body undergoing decomposition and the hands are badly charred or decomposed

Partition coefficient can be calculated from ...

from the concentration of the drug in the organic phase divided by the concentration in the aqueous phase.

Fingerprints are generated

from the dermal layer prior to birth

Weapons that can not be test fired in a water tank

fully automatic firearm, high caliber and shotguns

Mid-IR (4000 -1500 cm^-1)

functional group or diagnostic region

Universal Precautions

fundamental mechanisms to maintain the BBP standard and primary mechanisms for infection control

Cetus Corporation

furthered development of DNA profiling and molecular biology techniques with the development of polymerase chain reaction (PCR)

Silica melted at very high temperatures forms...

fused silica glass

In order to have a flaming combustion, both the fuel and the oxygen must be in the

gaseous state

Substage condenser

gathers light from the microscope light source and concentrates it into a cone of light that illuminates the specimen uniformly over the entire field of view

Refractory ceramic fibers

glass ceramic fibers

Issue with methods to perform elemental analysis of glass.

glass fragments are small, irregularly shaped, and often insufficient amounts for successful analyses

Surfaces Sudan Black works well on:

glass, metal or plastic, good for candles or wax-paper milk cartons

Function of Clearcoat

gloss and durability

Study Protocol: Experimental Design

goal is to obtain data in a statistically relevant manner, the analyses must be shown to be reproducible, large sample size, variables controlled, measurement more useful than observation, how subjects are selected must be discussed, ensure internal validity of the data by reducing bias by using the double-blind technique and cross-over experiments.

Distance Determination

grease dirt, unburned gunpowder and the pattern formed on the target can be used to estimate the distance and direction that the muzzle was

Advantages of Single Beam Spectrophotometers

greater energy throughput superior signal to noise ratios less cluttered sample compartments

What percentage of average ionization suppression/enhancement should would other parameters need to be reevaluated?

greater than 25%

Which of the following is a search pattern?

grid

Rifling

grooves cut into the inside surface of the barrel

Anagen Phase

growth phase, 85% of hairs, last from 2-6 years, approx. 10cm per year

a blood spatter pattern consisting of a large number of very fine, mist-like droplets indicates that the blood probably came from a

gunshot wound

What happens at the end of telogen phase?

hair follicle re-enters anagen and the dermal papilla and base of the follicle join together and a new hair is begins. If the old hair has not been shed it is pushed out

Structures in the epidermis and dermis

hair follicles, sweat glands, sebaceous glads, nails

Where is nuclear DNA found in a hair?

hair root, and if follicular material remains attached

Angel dust or PCP is what classification of drug

hallucinogen

Rifle

has a rifled barrel, bore diameter 0.17 to 0.50 inches, fires a single projectile

Polymorphic Drugs

have more than one form of crystalline structure

Amorphous solids ...

have no lattice structures and a lower melting point range of 10C

Injectors

heated to allow flash vaporization of the sample following injection, generally automated process, 1-3 micoliters vaporized

Examples of Schedule I Drugs

heroin, LSD, and marijuana

Semi-synthetic narcotics

heroin, hydrocodone, hydromorphone, and oxycodone

Schedule I Drug

high potential for abuse and no currently accepted medical use in the US

Fluorescent Dye Quinacrine

highlights the Y chromosome of freshly formed cortical cells in the hair root

Blood spatter patterns can indicate

how many sources of blood there were, what type of weapon was used, the number of times a weapon was used

Three conclusions of firearm examiner

identification, exclusion, or no conclusion

Confirmatory tests can...

identify a sample to the exclusion of all others

Fiber Diameters

if not uniform with in a sample a range of diameters should be noted

Tests for Brainstem Death

if the patient is having epileptic fits, there is decorticate or decerebrate rigidity, or "Doll's Head Eye Phenomenon" then the brainstem is alive

Reticular formation

ill-defined neural network at the top of the brainstem, generates signals that vary the level of consciousness

Pigment

impart color and opacity to the paint

Latent Prints

impression of the ridge characteristics from the sweat or oils that can stick to the ridge outlines

Two types of toolmarks:

impressions and striation marks

Advantages of Fluorescence

improved sensitivity over UV more selective since both excitation and emission wavelengths are important

How to store a powder/tablet?

in a dry, low stable temperature place protected from light.

Infrared analysis can be performed on samples:

in solution, as powders, as gases, as a halide disk

Where is mitochondrial DNA found in a hair?

in the hair shaft

Proper Controls ...

include positive and negative controls in the testing regimen

Developmental Validation (DNA)

include: characterization of the locus, species specificity studies, sensitivity, stability, and mixture studies a number of samples from a population must be obtained and analyzed in order for independence studies and allele frequency determinators to be made.

As numerical aperture of the total system ________ so does the resolution.

increases

Rate of Chemical Reaction

increases by a factor of 2-3 every 10degreesC rise in temperature

Reagent used for color tests

indicative of a certain class of drugs

Raman Scattering

inelastic scattering, scattered light has energy changes

Emitted X-rays on SEM-EDS produce

information regarding the presence of specific elements

Routes of Exposure

inhalation, skin contact, ingestion, injection

DeForrest

initiated the first systematic use of fingerprints in personal identification in the United States

Components in a GC

injector, columns, and detectors

The root has an ______ and ____ root sheath.

inner, and outer

Installation Qualification (IQ)

instrument installation and is usually performed by the vendor

Microscope

instrument that uses one or more lenses to magnify an object

A substrate control sample helps to detect

interference resulting in false negatives/positives

American Society of Crime Laboratory Directors (ASCLD)

international organization composed of crime laboratory directors whose mission is to promote excellence through leadership in a forensic science management

Manufacturing of Wire Glass

introducing wire mesh into the molten glass before it passes through the rollers

Product Ions

ions targeted in the third and final quadrupole that are sent to the detector

Why is leaded glass used for lenses, etc?

it is heavy and refracts light

In the laboratory, a drug sample is considered a false positive if:

it tests positive for a particular drug and none is actually present

Equation for Retention

k= t(retained peak) - t(non-retained peak)/t(NR)

Reference Fired Specimen File

known bullet and cartridge case specimens generated through water tank test fires

Facilities

laboratory operations should be removed from each other to prevent contamination, each room should be equipped to adequately handle the function for which it was designed, separation of air exchanges may be necessary, must be secure to ensure the integrity of the samples (check-point, key cards, keypads, id badges), guest must be escorted by personnel, exits in case of fire or other emergencies should NOT be limited.

The depressed helical grooves in a bullet are called

land and grooves

Oblique Cut

larger surface area created may facilitate layer visualization and assist in the detection of layer differences

Top-break revolver

latch at the top of the frame and the hinged barrel can be tipped downward to allow access to the chambers

Cross sections provide:

layer sequence, layer thickness, color, pigment distribution, pigment size, and composition of individual layers

Density Determinations test:

layering a number of miscible oils or liquids in a tube, heaviest at the bottom, the solution forms a uniform gradient and particles added to the tube will settle at the level of equivalent density

Compositions of Bullets

lead with partial or total encasing of copper, aluminum, steel or brass

Gunshot residue is characterized by the presence of the elements

lead, barium, and antimony

Leaded glass is used for

lenses, prisms and imitation jewels

Disadvantages of ELISA

less sensitive than RIA

Instrumentation laboratory

less sinks and more electrical power needed, ample floor space and benchtops, and access to all four sides of an instrument

Brainstem Death

less widely accepted idea that when the brain stem dies that the person is dead

Typical cuts of cocaine

lidocaine and procaine

Rubber lifters are used when:

lifting prints from curved or uneven surfaces

Variable Wavelength Detector

light goes through diffraction grating which is rotated to present the portion needed, desired wavelength is allowed to pass through a slit to a mirror and then the flow cell then a photodiode, transmission is recorded and converted to absorbance

Tests and Instrumentation for Glass Fibers

light microscopy, RI, solubility tests with HCl, fluorescence properties under UV, SEM-EDS for elemental composition

Cross sections can be examined and analyzed under:

light microscopy, UV-visible microspectrophotometry, infrared spectrophotometry, and electron microscopy

Plane Polarized Light

light of a single vibrational direction that is perpendicular to the direction of propagation

6 components of UV-VIS Absorbance Instrument

light sources, wavelength selector, cuvette, detector, signal processor, readout device

What are stabilizers in glass?

limestone or dolomite (calcium and magnesium carbonates)

Cost-reducing measures

limit accreditation to those methods being used, submitting applications for several procedures at once rather than successive single procedure submissions, combining the addition of newly accredited methods with an inspection visit, submitting accreditation applications by mail for labs with good track record Cost of accreditation = 25% of profit

Disadvantages of SBI with DAD

limited resolution 1-2 nm low specificity not all drugs absorb UV light addition separation technique may be need to remove interfering substances

Associative

linking people, places or objects

Sample Prep for FTIR

liquids in a sample cell, solids as thin films or dispersions or powder, mulls or alkali halide disks

The settling of blood in lower extremities of the body post mortem is called...

livor mortis

When collecting document evidence, it is important to carefully protect the document to avoid

loss of possible DNA, loss of possible indentations, loss of possible latent print evidence

Schedule IV

low potential for abuse relative to other schedules, currently accepted medical use, may lead to limited physical dependence or psychological dependence

Schedule V

low potential for abuse, currently accepted medical use, may lead to limited physical dependence or psychological dependence relative to IV

Advantages of LLE

low volume of solvent, vast amount of literature, relatively simple, low cost, optimized for different classes

Disadvantages of TLC

lower sensitivity and resolution than GC and HPLC, skill and experience necessary, subjective

Limit of Detection (LOD)

lowest concentration of the analyte that can be reliably detected and identified

Pearl-like finish paint has what in it?

luster or mica pigments in the basecoat

Rule of Thumb to Ensure Ionization

maintain pH that is 2 units above or below analytes pKa

Function of Reticular formation

maintenance of cortical activity in the rest of the brain

Fingerprinting Corpses

major case prints are obtained, use to identify/eliminate latent print evidence and identify the deceased

The polymerase chain reaction (PCR) is a process which ...

makes many copies of a specific piece of DNA

Advantages to fuming a print

makes transport of small items less likely to smudge or ruin the minutiae as it permanently affixes the print onto the surface

What is the erector pili muscle responsible for?

making hair stand erect and producing "goose bumps"

Y-STR tests are designed to specifically identify

male DNA profiles (y-chromosome)

How does clear glass become clear if there is iron traces in it?

manganese is added to offset the green and brown hues from the iron

Injection System (HPLC)

manual systems use a fixed loop filled with excess sample and holds the precise amount of solution for injection onto the column, extra sample goes to waste also automatic ones

Anisotropic

materials with 2 or 3 RIs, aka fibers

Isotropic

materials with one RI, aka glass

Ionization Suppression/Enhancement (LCMS)

matrix components that elute near the time of the analyte of interest can impact transmission of the analyte ions to the MS

Calibrators to make the Calibration Curve

maximum 120% of expected maximum concentration minimum 10%> than the minimum quantifiable value 4 to 7 used dependent on the range to be quantified minimum of 3 control samples, at low (10%greater than min calibrator) medium and high (10% less than maximum) concentrations values

How to measure TLC spots?

measure from the middle of the spot but oval then the center of the densest area should be used

Numerical Aperture of a Microscope Objective

measure of the objectives ability to gather light and resolved fine detail at a fixed object distance

Fluorescence Spectrophotometry

measures light that emitted from molecules that are excited to higher energy levels after the absorption of light

Manufacturing of window glass

mechanically is drawn through a slotted block ,that is under the surface of molten glass pool, into an annealing furnace, once through the furnace it is cut into sheets

Action

mechanism for firing, loading and unloading

Serial Number Stamping on the Weapon

metal is compressed below the actual stamp, therefore it is possible to restore the number by applying chemical agents that etch the surface of metal

Barrel of a firearm

metal tube produced by drilling out a steel rod, typically has rifling on the inside

Typical bullets for semi-automatic weapons?

metal-jacketed bullets

Synthetic narcotics

methadone, fentangy, meperidine, propoxyphene, and pentzocine

Official SOP's

methods outlined for many routinely analyzed compounds that can be Environmental, Clinical and Pharmaceutical, Manufacturing Prior to SOP use, the accuracy, precision, selectivity, reproducibility, and repeatbility of a method must be demonstrated before it is actually used

Training on Chemical Hazards should include:

methods to detect presence or leakage of hazardous chemicals, details of physical health hazards associated with hazardous materials in the work area, safety measures workers may use to protect themselves

For the examination of suspected cannabis what tests might be conducted?

microscopic examination for morphological features such as clothing, cystolithic, and glandular trichomes, Duquenois-Levine and Dragendorff's color tests.

Tests on Hashish

microscopy still be used and spot test and TLC

Any two of these tests identifies marijuana

microscopy, color test or TLC

Fiber Dye and Color Tests/Instrumentation

microspectrophotometer, TLC or HPLC

photographs of crime secenes must include overall views, close ups, and _______?

midrange

Molecular label

might be a totally separate molecule from the antigen, or a modification of it

How to separate glass from mineral grains?

mineral grains will be anisotropic and glass will be isotropic under cross polar polarized light

Porous Evidence Disadvantages

minutiae may be lost as the residues expand

Paraphernalia for cocaine use:

mirrors, razor blades, tube, or various pipes

Primer

mixture of chemicals that detonate upon impact of the firing pin which then ignites the propellant

Paint

mixture of pigment and binder dissolved or dispersed in a solvent

Gradient

mobile phase gradually changed throughout the run

Isocratic

mobile phase kept constant throughout run

Thin Layer Chromatography (TLC)

mobile phase moves across a thin, uniform layer of finely divided stationary phase by capillary action.

Disadvantages of Electrochemical

mobile phases must be electrically conductive high maintenance

IR Principle

molecules have specific frequencies of internal vibration, total energy of a molecule is the total sum of its translational, vibrational, rotational and electronic energies

Materials absorb energy causes...

molecules to oscillate, inducing electric and magnetic fields which generate an electromagnetic wave or light

Manufacturing of Float glass

molten glass is floated on top of a bed of molten tin at high temperatures that enable imperfections to be removed by the fluid flow of the glass

Raman Spectroscopy

monochromatic lasers impinges on the sample, the incident light interacts with the molecule exciting it causing it to emit photons and causing light to scatter. Which is then measure depending on the type

Advantages to Fluorescence Spectrophotometry

more sensitive and more specific than UV-Vis

Natural narcotics

morphine, codeine, and thebaine from the opium poppy

Animal Fibers

morphological features of animal hair, except silk

What is the advantage of SEM analysis of GSR?

morphology of the gunshot residue particles as well as identifying the elemental composition

Reversed-phase

most frequently used nonpolar stationary phase with polar mobile phase

Advantages of UV-Vis Detector

most organic compounds absorb UV light sensitive to the ng/ml level

Gunshot Residue can be lost by:

movement, washing, wiping or environmental conditions

Shed head hair has

mtDNA only

Preconditions for Brainstem Death

must be comatose and incapable of breathing on their own, cause of come must be known beyond doubt, irremediable structural brain damage

Internal Validation (DNA)

must be conducted by any laboratory when developmental validation has been performed by another laboratory or at another site of a multi-site laboratory

Negative Sign of Elongation

n(parallel) < n(perpendicular)

Positive Sign of Elongation

n(parallel) > n(perpendicular)

Chemical Label Requirements

name of chemical, picture hazard, symbol hazard, word hazard, name and address of manufacturer, importer or other responsible party

Chemical Inventory Includes

name of the chemical, approx quantity, storage location, date of acquisition Dependent on Lab: manufacturer, quantity used, exp date, hazards, CAS #

Interference

natural constituents of samples that can be co-extracted during residue analysis and need to be recognized, ex. Br in veggies, S is soil, CS2 in crops

Measurement Uncertainty

need to account for all potential sources of systematic and random error of the chosen method and then report the uncertainty with an associated coverage factor and confidence level

Dilution Integrity

need to be assess for scenarios where the analytes concentration is outside the upper end or is low volume sample

Biological Waste

needs to be disposed of separately and not mixed with regular lab waste

State of glass

neither solid nor liquid, in a vitreous/glassy state

Instruments to be used in Hair Individualization

neutron activation analysis, ion microprobe mass analysis, and pyrolysis-gas chromatography

Training Programs Provided When:

new plan/procedure is developed, for all new employees, when new equipment, materials, or processes are introduced, procedures have been updated or revised

Hydranencephaly

newborn children that exhibit persistent vegetative state

Next Generation Identification (NGI)

newest identification program, slated to replace IAFIS as the premiere identification tool nationwide, encompasses a wide array of biometrics

Diazafluoren (DFO)

ninhydrin analogues, reacts to amino acids in body proteins

Single base smokeless powder

nitrocellulose

Double base smokeless powder

nitrocellulose and nitroglycerin

Physical Decomposition

no change in covalent bonds of drug, but involves changes to the crystal lattice structure.

Is window glass uniform thickness?

no it is not due to how it is manufactured

Shotgun

no rifling, larger bore, fired multiple types of projectiles (slugs, buckshot, and shot bird)

The caliber of a weapon is

nominal indicator of bore diameter, diameter between upper surfaces of opposing lands

The majority of DNA is ...

non-coding

Clearcoat

non-pigmented, acrylic or polyurethane based

Disadvantage of Color Tests

non-specific, destructive and may be affected by the conditions of the test

X-ray Diffraction (XRD)

nondestructive technique, identification of the crystal form of pigments, extenders or fillers

Surfaces to use Sudan Black

nonporous surfaces contaminated with greasy, oily, and sticky substances

Why is UV-VIs a screening test?

not all drugs absorb UV light

Disadvantages of X-ray Detection

not very convenient

Mathematical Expression of RI

nr = velocity in first medium / velocity in second medium

Efficiency

number of theoretical plates needed for separations

First truly synthetic fiber was:

nylon

Most important component of an optical microscope:

objective lenses

What determines the quality of images the microscope is capable of producing?

objective lenses

Overtone Absorption

occur at frequencies that are multiples of the fundamental band frequency

Combination Absorption

occur at frequencies that are the sum or difference between two or more fundamental bands

Operational Qualification (DQ)

occurs when the instrument is tested and shown to meet previously set (frequently by the vendor) specifications more sophisticated instruments vendor performs this simple instruments laboratory personnel can do it

How to protect the scene?

officers protect they scene by physical presence at established points outside the inner perimeter

Glandular hairs/trichomes are found

on flowering and fruiting tops, leaves and stems, and have a spherical shaped head and contain an oily resin

Clothing hairs/trichomes are found

on the underside of the leaves and are long, sharply pointed hairs

Performance Qualification (PQ)

on-going process that is conducted by the laboratory personnel in order to demonstrate that the instrument consistently performs up to specifications for each analyte that will be analyzed in the laboratory or to perform the correct sizing for each locus used for DNA systems

Bloodborne Pathogen Training

once a year if the personnel is exposed to them Hep B vaccinations must be made available to an employee within 10 days of an assignment to a position involving bloodborne pathogens universal precautions and engineering controls practiced. Equipment and lab surfaces are cleaned and disinfected. All areas contaminated with biological waste must have fluorescent orange or orange-red labels with the biohazard symbol

Animal Care Facilities

one species per room (aquatic animals exempt, different tanks same room) separate rooms should be used for studies involving biohazards, volatiles, aerosols, radioactive or infectious. animals should not be housed within individual laboratories, designated areas of the lab can be used sick animals should be isolated environment of the room can be altered according to the study protocol storage areas for feed and bedding are required access should be limited to personnel

As the condenser diaphragm is ________ the working numerical aperture of the microscope increases

opened

Becke line

optical artifact at the boundaries of the glass that changes bases on the difference between the RIs

XRD is not suitable for the identification of

organic pigments

ASCLD Laboratory Accreditation Board (ASCLD-LAB)

organization that has published minimum standards for laboratories and their personnel to achieve, following formal accreditation by the organization

Refractive Index

other than glass fibers, have two principles RIs, plane polarized light passing through the fiber is retarded in the direction of the slower ray, the amount of retardation can be estimated by observing the change in interference color at a point where the thickness of the fiber is know by using the Michel-Levy chart

Reference Firearms Collection (RFC)

over 5000 firearms available as a reference for the identification of evidence

Examples of Schedule V

over the counter cough medicines with codeine

Columns (HPLC)

packed column, short in length but have wider diameter than GC

Solvent/microchemical tests can discriminate between

paint films with different pigment and binder composition but indistinguishable by visual and macroscopical appearance

Individualizing friction ridge detail also exists on your

palms, fingers, and feet

What surfaces can SPR be applied?

paper, cardboard, new, rusty and galvanized metal, bricks, rocks, concrete, plastic, vinyl, wood, and glass, wet surfaces, from rain or submerged, can be used underwater, non-porous sticky-side tapes

Examples of porous evidence

paper, unfinished wood, cardboard

National Institute for Occupational Health (NIOSH)

part of CDC and has responsibilities for investigating potentially hazardous working conditions, evaluating hazards in the workplace and conducting research providing scientifically valid recommendations for protecting workers

Quality Control (QC)

part of quality management focused on fulfilling quality requirements

Antibodies

part of the body's immune response designed to bind to and assist with the deactivation and elimination of foreign invader

Changing the pH Environment

passing a buffer through the column to make the environment conductive to the retention of the analyte of interest onto the column.

Hallucinogens

phencyclidine (PCP), lysergic acid diethylamide (LSD)

Bathochromic Shift

phenolic compounds the solution is more alkaline leads to an absorption shift to a longer wavelength (red)

2nd Step of Fingerprint Detection

photograph and collect all indented and visible prints, special lighting and techniques used

Paul Jesrich

photomicrographs of bullets for comparison purposes

Electromagnetic radiation consists of:

photons

anti-Stokes scattering

photons can end up at a lower energy state

Factors that affect visibility of latent prints

physical condition of the person who left the print, surface of object, lighting angles, elapsed time since the prints were placed, amount of heat exposure, constituents of the print

Basement membranes provides:

physical dividing line between epidermal and dermal cells and is a physical barrier vital to our immunological protection

Most conclusive type of examination performed on paint samples:

physical matching of sample

Classification of Arches

plain arches, tented arches, an gular, up thrust

When ionized analytes are more polar therefore in a reversed-phase would prefer...

polar mobile phase

Cross-reactivity (IA)

polyclonal antibodies are not specific therefore can react with antigens of similar molecular structure

Genetic differences among people that enable them to be distinguished are called genetic ___?

polymorphisms

Results in a greater error than the sum of all errors by laboratory analysis alone

poor sampling protocols

First step of glass examination

possibility of physical fit

Disadvantages of FPIA

possible background interferences, inhibited by extraneous molecules

Heat Effects

possible to observe droplet formation, contraction, softening, charring and melting of fibers over a range of temperatures

Presumption of Death

possible to register a death even if no body has been found or no direct evidence that death has occurred

Applications of IAs

postmortem investigations, workplace drug testing, human performance investigation

Fine-quality glass or glass crystal is made from:

potassium-silicate formulae that includes lead oxide

Schedule III

potential for abuse less than schedule I or II, currently accepted medical use even though abuse of the drug may lead to moderate or low physical dependence or high psychological dependence

Most common process for processing latent prints

powdering or chemical treatments

the rough sketch that is usually prepared at a crime scene is used to

precisely locate evidence

Delustrant Particles

presence or absence the size, shape, distribution, relative abundance

Advantage of Tape lifting fingerprints

presenting the lifted impression in the correct orientation

Porous Evidence Advantages

preserve prints well because residues soak into the surface, preventing superficial removal

Forensic Anthropology

primarily associated with the identification of skeletal remains

Cystolithic haris/trichomes are found

primarily on the upper side of the leaves, small bear claw shape and have a calcium carbonate base

Fundamental Absorption

primary absorption bands for each mode of vibration

2nd layer in paint

primer

Centerfire cartridges

primer in the center and the firing pin hits the center

Disadvantage of rubber lifters

print is reversed

Cyanoacrylate Fuming on Non-porous surfaces

print residue becomes polymerized and hardens, improving the ability to observe and possibly lift the developed print pattern

Disadvantage of ESDA

prints must be fresh for significant results

Analysis

prior to analysis the sample should be stored in a secure location with an unbroken seal, dilutions, measurement of pH and weight, duration time for processes such as extractions, amplifications, prep vol of reagents and stds., each step must be documented, for confirmation purposes another analyst should be there to observe OR another confirmatory test can be performed, all evidence should be documented with a sample ID #, date of analysis, ID of instruments used, approved methods number

How often is PQ done on instruments with heavy use?

prior to use or daily

intentional adulteration

process of adding an impurity or inferior substance ex. food industry adding fillers, selling frozen fish as "fresh"

Design Qualification (DQ)

process of selecting the specifications for and purchase of an instrument

Latent Prints in Blood

processed using specialized light techniques

How to preserve prints on small, non-porous objects?

processed with cyanoacrylated at the scene

Polyclonal Antibodies

produced by the animal in-vivo

Victor Balthazard and Marcelle Lambert

produced the Hair of Man and Animals detailing the use of microscopical analysis to compare and observe morphological features

Kohler Illumination

produces even, glare free, specimen illumination across the entire field of view

SEM works by

projecting an electron beam over a selected area of a sample, producing emission of signals including x-rays, backscattered electrons and secondary electrons.

Hans Gross

promote criminalistics by applying scientific knowledge and methods for the interpretation and analysis of physical evidence in crime investigation and established a journal dedicated to forensic science

Physical Match between recovered chip and possible source would be regards as

proof of origin

William Herschel

proposed the application of Fingerprinting for personal identification

Sample stability/storage

protect samples from moisture, heat and light.

Function of electrocoat primer

protection against rust

Crystal Violet

protein dye that stains the fatty components of sweat a deep purple color, can be used for bloody fingerprints

Amido Back

protein dye, sensitive to blood proteins, turning a blue-black color, does not stain normal constituents found in print residues

Silk

protein fiber, crossover marks and triangular cross section with rounded corners

Due to Penetration Depth on XRF

provide elemental data from all layers of a typical multilayer paint fragment simultaneously

Microspectrophotometry

provide objective color data from small samples

Chemical information management system (CIMS)

provides the ability to store and work with chemical structures and rxns

Verficiation

provision of objective evidence that a given item fulfills specified requirements

Functions of Brainstem

provision of supply to the twelve pairs of cranial nerves which mediate smell, sight and eye movement, taste, hearing, facial touch, swallowing, control of heartbeat, breathing and visceral activity

Active agent in psilocybin

psilocin, responsible for the behavioral effects

Drug dependency is subdivided into two categories

psychological and physiological

Victor Balthazard (1910-1920)

published the first scientific article on the significance of bullet marking and their relation to bullet individualization

Francois Demelle

published the first study on questioned document examination

Load the sample

pulling the sample through the column without allowing the column to dry out but allowing the sample to pass through in a dropwise fashion

Double Action Firearms

pulling the trigger will cock and release the hammer

Sample Prep when using Microscopy onFTIR

pure compound can be crushed onto a KBr disk

The process by which solid materials are decomposed by heat, forming smaller molecules that can support flaming combustion is called

pyrolysis

Linear Ion Trap (LIT)

quadrupole like design coupled with electrodes on each of the end to trap the ions

Problems behind the factors that affect reproducibility (TLC)

quality of the binder or absorbent, impurities or diff in thickness of the phase on the plate, impurities in the solvent, ill fitting lid, unequilibrated solvent vapors, solvent runs faster when warm, volatile substances evaporate faster and Rf values tend to decrease, increased Rf with an increase in running distance due to evaporation of solvent from the upper part of the plate, and increased mass will increase Rf

Bias

quantitative measurement used to assess trueness and is defined as the closeness of agreement between the mean and the reference value, assess systematic errors

How to avoid contamination of fiber evidence?

question and known items are examined in separate area and area and tools are thoroughly cleaned and lab coats changed

Advantages to SBI with DAD

quick data accumulation simple design few moving parts little calibration needed Minimal maintenance required Used for quantitation

Advantages of FTIR

quick data collection all frequencies detected simultaneously scan sample 10 times per second increased sensitivity increased spectral resolution enhanced data manipulation

8 different fingerprint patterns

radial loop, ulnar loop, double loop, central pocket loop, plain arch, tented arch, plain whorl, accidental

Radial fractures

radiate out from the center of the penetration site, they form first, they start on the opposite side of the pane that the impact occured

Ionizing Radiation

radiation from alpha-, beta-, gamma-, and x-rays, high speed electrons or protons, neutrons, and atomic particles

Single Beam Instrument with a Diode Array Detector

radiation is focused on the sample then passes through a monochromator with a fixed diffraction grating. The dispersed radiation is reflected onto a photodiode transducer that is composed of hundreds of photodiode array transducers mounted on a silicon chip. The slit width of the monochromator is adjusted to the width of one of the diodes so the output of each diode corresponds to radiation of a different wavelength, by scanning these outputs sequentially a spectrum can be obtained.

Fourier Transform Infrared Analysis (FTIR)

radiation travels from the source to the beam splitter where half the radiation is reflected onto the fixed mirror, the other half reflected to the moving mirror. The beams are then reflected back towards the beam splitter where half of the recombined beams are transmitted to the detector while the other half is reflected back to the source, the detector an interferogram is formed

Friction Ridges

raised portions and furrows on the skin on the inner surface of the hands, fingers and soles of feet

Range of Standard Curve

range of analyte concentration that the method being assessed can consistently identify

Important in cases of person contact including:

rape and homicide

Advantages of Raman

rapid no sample prep detect through some packaging portable nondestructive quantitative and qualitative

Manufacturing of tempered glass

rapid heating and cooling cycles

How long does GSR last on a person?

rarely beyond 3 hrs

Medullary Index

ratio of medulla to the overall hair shaft diameter

Protolytic or protolysis Reactions

reactions where an acid reacts with a basic solvent or in which base reacts an acidic solvent to form conjugates.

Criminalistics

recognition, identification, individualization, and evaluation of physical evidence using the methods of natural sciences in matters of legal significance, aka the science of individualization

Erythrocytes are also known as:

red blood cells

What color do the latent prints appear when processed with ninhydrin?

reddish-purple to brownish-purple

Engineering control

reduce potential hazards by isolating or removing the hazard from the work environment

What have a coating on the bullets?

reduces fouling of the bore and allows the bullet to travel more easily through the barrel

Equipment

refers to freezers that store samples, thermometers, thermal cyclers, automatic pipettes, hood ventilation system, also items that measure some parameters are called more specifically instruments

Fluorescent Powders

regular or magnetic, need to observe the developing of the print under UV light source

Linearity/Calibration Model

relationship between the concentration and response

What to look at to determine if human or animal?

relative size and appearance of medulla, appearance of the scales and diameter of the hair shaft

Plant Fibers

relative thickness of cell walls and lumen, cell length, and the presence, type and distribution of dislocations, direction of twist of the cellulose

Determine Precision

replicate analysis of 3 samples of 3 different concentrations performed on the same day and over a minimum of two weeks

Quality Control

replicate control samples are spread evenly throughout each batch so that a control sample is injected at least every 10 samples and each control sample is done at least 3 times.

Disadvantages of SPE

require vacuum, more solvent than LLE, additional sample prep needed, operator dependent, cartridges can be clog

Wet Chemistry Laboratory Requirements

requires adequate sinks, hoods, etc. Storage cabinets appropriate for chemical needs.

Transmission Microspectroscopy

requires consistent sample thickness and choice of measurement size and location for meaningful comparisons

Alphonse Bertillon (1902)

responsible for the first criminal ID of fingerprint without known suspect; matched print from the scene to prints on file

Telogen Phase

resting phase, final phase, lasts 5-6 weeks, does not grow but stays attached to the follicle while the dermal papilla stays in resting phase, 10-15% of all hairs

Bio-Materials Lab

restricted access--this minimizes the # of people exposed equipped with biological safety cabinets that have HEPA filters to protect lab personnel and protect cell cultures changing into other clothing may be needed if working with dangerous biological material

Study Protocol: Start and Finish Dates for Study

retention of all experimental records is necessary, this includes hand-written observation, raw data obtained, protocols, data, documentation, reports an even specimens must be saved for some time (non-clinical study w/ application= 5, no application = 2 yrs) -this is mandated by the FDA EPA requires 2-5 yrs retention of record based on whether or not the results of the study are submitted to the EPA, clinical drug regulations state that records must be retained for two years after marketing approval or notification that the study was discontinued Protocol Approval - signed and dated by the sponsor and study director. Also signatures by quality assurance officers, consultants and others Statistical Methods-statistical methods should be summarized and rationale for their use included. Appendices--Ex. of the Informed Consent Form, SOP's, Ex of Owner consent form (animal), descript of collection sites, descript of special equip, validation studies, investigator qualifications

Calibration Curve

reveals the instrument's response to the concentrations analyzed

The corpse becomes rigid due to biochemical changes post mortem is called...

rigor mortis

Mineral wool

rock wool and slag wool

Manufacturing of Plate glass

rolling glass sheets continuously between double rollers, then annealed, both sides are finished continuously and simultaneously

Types of crime sketches include

rough, cross-projection, final

High velocity projectile patterns

round crater-shaped hole with almost symmetrical pattern of radial and concentric cracks, the hole is wider on the exit side

Bullet styles

round nose, wadcutter, semi-wadcutter, full metal jacket, soft point, hollow point, and semi-jacketed hollow point

Lifting of the Print

rubber lifters or transparent lifting tapes

Size Exclusion

sample analytes being separated based on size, larger molecules followed by smaller molecules

Surface Enhanced Raman Spectroscopy (SERS)

sample is adsorbed onto a metal surface prior to analysis leading to a higher signal

Fluorescence (HPLC)

sample is irradiated with UV light to cause excitation of the molecule and the molecule emits a second wavelength

Transport of Test article tracking

sample must be maintained under appropriate conditions during transport from the field to laboratory, when biological liquid samples are involved they should be placed in a water proof closure inside the sealed shipping container, chain of custody (COC) should also be included during transport that states: name and address of the requesting company, list of samples with ID #, type of sample, manner of collection, test (s) requested, name and address of testing laboratory, signature of person delivering sample, signature of person receiving the sample. Shipping ctgr should be sealed or locked. Save all packaging and inspect for evidence of tampering.

ATR-FTIR

sample placed directly on an IR transparent crystal with a high RI, IR radiation enters the crystal at a specific angle, crystal acts as a prism causes internal reflectance. An evanescent wave is created and protrudes into the sample, the sample absorbs energy and the evanescent wave will be altered/attenuated, the attenuated portion of the wave continues to the detector creating the spectrum

Sample Contamination

samples must be separated from each other, and other sources of contamination, during transit, storage and analysis. Of utmost importance when dealing with volatile compounds and concentrates. examples of samples commonly contaminated during analysis--- rubber and plastic items--lubricating oils in gloves, CS2 from handling veggies/fruit drinking water--disinfection by-products

Storage of test articles

samples should always be stored to minimize degradation, loss, and contamination, they also should be secured to prevent tampering. The storage document must be linked to the sample analysis document. Disposal of samples must be documented, for DNA samples a portion should be retained

What is the first thing a first responder should do at a major crime scene?

search for and detain the suspect

3rd Step of Fingerprint Detection

searching for latent prints

First Responsibility of the Responding Officer

secure and protect the scene

Waste Collection

segregated and prepared for collection according to the procedures issued by OEHS

What are the advantages of solid phase extraction compared to liquid-liquid extraction?

selectivity, reproducibility, and speed

Advantages of SPE versus LLE

selectivity, reproducibility, speed

Semi-Automatic Weapons

self-loading, difference methods of the loading

Heroin

semi-synthetic compound

Thermal FTIR Detectors

sense a change in temperature of the absorbing material deuterated triglycine sulfate (DTGS) detector

Advantages of Color Tests

sensitive and fairly quick

Advantages of Electrochemical

sensitive to pg/ml levels selective

Contamination Prevention:

separate areas for mixing of the test separate control and reference substances with a carrier storage of the test, control, and reference substance mixtures separately separate areas for pre and post amplified DNA extraction and amplification should be separate areas examining reference samples and evidence should be done separately

Split Injector

septum purge remains open, allowing flow of carrier gas to minimize any potential extraneous peaks that could result from the septum itself, moves the sample through the column or the split vent, amount of sample reaching the column is dependent on the ratio

Antiserum

serum drawn from the animal that antigen-specific antibodies are found in

Edmund Locard

set up first police crime laboratory in Europe, in Lyons, location of Interpol today

Paul Kirk

set up the first academic criminalistics program in the United States at the University of California, Berkeley in 1937 and also further developed the technique of har comparison by utilizing various physical and chemical properties to attempt to facilitate systematic individualization of human hair

Class Characteristics Toolmarks

shape, dimensions of working surface, distance between teeth of a saw, etc

Hypochromic effect

sharp fall in absorptivity

Large Glass Sample's RI can be measured directly

shining light (sodium light at 250nm) through it and measuring the degree of refraction

Magnetic Powders

shiny magazine covers, boxes with a coated surface, some plastic materials

Eyebrow and eyelashes

short, curved with finely tapered tips, thinner diameter than pubic hairs

Pubic Hairs

shorter than head hair, curlier, flatter cross-sections, medulla usually continuous, fluctuations in diameter, tip abraded but somewhat tapered

Rolled Impressions

show the entire friction surface of the finger or thumb, tip to 1/4 inch below the first join

Photographs can help determine what in toolmark examination?

show where the toolmark was located in relation to other objects and aid in determining how the tool was used

Physical Developer (PD)

silver-based liquid reacts with lipids, fats, and oils, works well for porous objects, last of the processed used

Axillary Hairs

similar to pubic hairs though less diameter fluctuations

The method for testing for ignitable liquids that uses a syringe to collect samples is the ...

simple headspace

Advantages of TLC

simple, cheap, reliable, selective, run several samples at a time, non-destructive, flexibility in mobile and stationary phases

Advantages of Attenuated Total Reflection (ATR)

simple, rapid, non-destructive, less than a milligram of sample used, solid and liquids

Two types of smokeless powders are:

single base and double base

4 microscopic characteristics that can be used to determine positive or negative microcrystal test:

size, habit, color and aggregation of crystals

The ______ the droplet, the ______the force that was used to create the spatter

smaller, the greater

Resolution of a Microscope Objective

smallest distance between two points on a specimen that can still be distinguished as two separate entities

Propellant

smokeless powder, typically nitrocellulose

Function of Primer

smooth any fine imperfections in the surface

Why is hair mounted in a medium with a refractive index close to that of the hair?

so that light is transmitted and not reflected from the surface

Lime is added to glass to prevent...

soda glass dissolving in water

Typical diluent of cocaine

sodium bicarbonate

Things to observe during solvent/microchemical tests

softening, swelling, curling or wrinkling, layer dissolution, pigment filler effervescence, flocculation and color changes

Analytical Techniques for Paint

solubility tests, color characterization by microspectrophotometry, microscope FT-IR, Pyrolysis-GC, X-ray fluorescence neutron activation, and inductively coupled plasma-MS

Electrochemical (HPLC)

solutes undergo oxidation or reduction at the surface of an electrode with the measurement of the resulting current

Standards Solutions

solutions of drugs or chemicals of known concentration

How preserve prints made visible by foreign substance?

sometimes by using print lifting tape

Palm Prints

sometimes found at the seem, whole hand makes a distinctive impressions

Three Major Components of Fourier Transform Infrared

source of radiation, a interferometer and a detector

Resolution

space between peaks

Radioactive Materials lab

special room design, fume hood with Pb glass and HEPA filter may be needed, all surfaces and equipment checked for radioactivity regularly

Pulsed-spitless Injection

spiltless mode proceeds by injecting larger volume of sample and increasing inlet pressure for a short period of time, which rapidly properls the sample onto the column

Spitless Injection

split vent value is closed and carrier gas and sample flow through the inlet to the column allowing the full volume to be deposited onto the column, low concentration samples

Preliminary /Screening Tests for Drugs

spot (color) tests, microcrystal tests, UV spectrophotometry, chromatography, and tablet/capsule markings

Sudan Black

stains the fatty components of sebaceous gland secretions

Headstamp

stamp on the cartridge case that indicates the caliber and manufacturer

Persistent Vegetative State (PVS)

states of cognitive death

Reverse-phase system

stationary phase is less polar than mobile phase

Adsorption / Normal Phase

stationary phase is more polar than the non-polar mobile phase used for non-polar to moderately polar materiasl

Normal phase system

stationary phase more polar than mobile phase

Descriptive Considerations

statistic techniques that collect, organize, and analyze the data without drawing any conclusion or inference, used by labs performing routine analyses (ex. level pesticides in soil, creatine in blood, controlled substance in sample) Assumptions made include--data having a bell-shaped curve (Gaussian distribution), errors that random and independent of outside influences

Preparing for External Inspection

steps to prepare include: laboratory clean-up, review each facet of the lab operation for compliance, organize each operation for easy review by the auditor

When a fracture line in glass hits a pre-existing fracture line it....

stops

Chemical Waste

stored in a separate area from chemicals

Individualization characteristics from the bullet

striation marks on the bullet as it passes through the barrel, due to imperfections introduced during manufacturing of the weapon

Infrared (IR) Spectrophotometry

study of reflected, absorbed, or transmitted electromagnetic radiation of wavelength

Hypodermis

subcutaneous tissue under the dermis, connective tissue, fat cells, macrophages, fibroblasts, blood vessels, nerves and base of the accessory glands

Typically cutting agents of heroin

sugar, brick dust, ground vitamin tablets, and household cleaning agents

Cyanoacrylate Fuming

super glue reacts with amino acids, fatty acids and proteins in the print and the moisture in the air, producing a visible, sticky, white material along the ridges of the fingerprint

Serial Number Restoration Process

surface is cleaned and polished, an etchant is carefully applied with a cotton swab, numbers are photographed as soon at they appear, surface is then neutralized, rinsed and preserved with a lubricant

Fiber Surface Characteristics

surface striations from the manufacturing process

Wet blood stains should be collected by

swabbing

Most fabrics are made form:

synthetic fibers

Fibers- Infrared Analyses

synthetic fibers chemical compositions can be determined, with microscope IR, by comparing to fiber reference spectra, should be done before dye extraction

Classifications that fibers are tentatively group in during examination:

synthetic, natural, or inorganic

Paraphernalia of heroin

syringes, spoons, cotton and aluminum foil

Homogeneity of Solution

taking aliquots from the top, middle, and bottom of a sample. Concentrations for each aliquot should fall in a previously determined acceptable range

Diffuse Reflectance (DR)

technique applied to the outer surfaces of paint films on the microspectrophotometry

Modification of an SOP

temporary adjustments are needed for an SOP due to: --A specific grade of solvent or reagent is currently unavailable --Impurities if a sample may require an additional extraction step --The analysis includes additional analytes When SOP's are changed a single line should be drawn through the changes and initials (of the modifier) must be placed next to line

Analyzer

term for the second polarizing filter

2nd step of firearm examination

test fire is chosen and compared with the evidence

1st step of firearm examination

test fires are compared to each other to determine if the weapon produces reproducible marking each time it is fired

How to separate plastic from glass?

test for indentation with a needle, glass will not be indented

For linear relationships (between concentration and response)

test results should be eval by appropriate statistical methods. Ex. by calculation of least squares regression line, min of 5 concentration is reccomended to establish linearity

Condenser aperture diaphragm controls

the angle of the light cone reaching the specimen

Refractive Index (RI)

the change of direction of the light upon encountering differing light waves in the two medias

What determines melting temperature of glass?

the composition of the specific glass

Cut Off Levels

the concentration used to distinguish between positive and negative results

Reporting Accuracy

the difference between the mean and the accepted true value together with the confidence intervals

Rf values

the distance the substance travels from the origin divided by the distance the solvent front travels. If the substance is a spot you measure from the middle of the spot, but if the spot has a tail then you measure from the densest area of the tail.

pesticide tolerance levels

the enforceable limit of pesticide residue that is allowed on food items

Inspection (Definition)

the examination or measurement of an item or activity to verify conformation to specific requirements

Toolmark examinations may provide the following information

the kind of tool used to make the mark

Quantitation Limit (LOQ)

the lowest concentration exhibiting acceptable bias and precision, can be determined through signal to noise ratio or using approaches to determine LOD

Exhibit should be initially examined to verify

the packaging is intact and no evidence of tampering, and accompanying paperwork for inconsistencies in the chain of custody

The three components of a cartridge case are

the primer, the propellant, and the bullet

UV-Vis Spectrophotometry

the principle that substances absorb and emit electromagnetic radiation at different wavelengths and provide an absorbance spectrum and determine the concentration of a substance in solution

Due diligence

the process by which data is generated to demonstrate compliance with statutory limits is commonly referred to as this

Stock

the rest of the gun that the other components don't cover

Haft shaft below the surface is:

the root

What are some parameters that affect the Rf value of drugs separated by TLC.

the stationary phase, temperature, the mobile phase, and the mass of th esample.

Solvent effects

the strength of the acid or base is dependent on the solvent it is in

Equipment Inventory

there should be an inventory of all equipment in the laboratory, they should all have a unique ID #, and have a file

Types of FTIR Detectors

thermal and quantum

Archiving Records

these can be used to: establish where samples were at all times (confirms that the sample could not have been possibly been misidentified), shows that ukn persons could not have tampered with the sample, show that analytical procedures for the sample were followed, interpret data independently These records are really important to forensic evidence bc lawyers often challenge the results of scientific tests

Electronic Records

these records can be stored on a variety of media from 3" disks to CDs to computers. Limited access must be given for info stored on computers to prevent alterations and deleting info., 2 copies should be kept and stored at different locations STORAGE requirements all storage media have finite lifetimes, choice of storage media depends on--amount of data the medium can hold, ease of use, reliability, depends a specific operating systems, period of time the records need to be saved

Physiochemical factors

things that affect drug decomp rates include temp, catalysts, pH, nature of solvents extra drug adulterants can also affect the stability of the drug

Laboratory Information Management System (LIMS)

this is used to: track samples, test results, schedule work, store information about equipment, record standard operating procedures (SOPs)

Specificity

this is when a test can discriminate between compounds of closely related structures like drug metabolites. This can be demonstrated by obtaining positive results from the samples containing the analyte and negative results from the samples that do not contain the analyte. The assay should be applied to structurally similar or closely related substances to check for specificity.

Role of the Archivist

this person is responsible for the ID, maitenence, preservation, and use of all records. typically a member of the quality assurance team interested in both the physical preservation of documents and samples and also interested in the contexual relationship between all the items ex. GC-MS quantation of urinary drug levels that can be accessed and used in a forensic case

Establishing Accuracy

this should be established across the specified range of the analytical procedure

Internal Audit checklist

this type of audit can be a way to prepare for inspection by a regulatory agency, this can be done by lab personnel, one who is familiar with the equipment, but not specifically involved in that program. Typical checklist includes: names of staff members must haves--unique ID, COC, proper seal, samples protected, ID's based on 2 independant assays, amount of sample needed, security Receiving through confirmation: check new SOP's, interview employees, check freezers and fridge, check for samples left out or unattended, check receiving paper work, verify COC Check written policies---contamination issues, sample tampering, breakage, ect

Accreditation Process

to do this a laboratory must demonstrate that it fulfills all the requirements est by the appropriate regulatory bodies, this is demonstrated through a laboratory audit that is conducted by an external, independent expert. In addition, proficiency testing for certification of each analyte must also be done. Analysis of an ukn sample done correctly. Ex. EPA lab analzyes CCl4, benzene or styrene via GC-MS

Function of Friction Ridges

to increase friction when fingers grasp an object

Samples are derivatized prior to GC analysis for the following reason:

to increase stability at elevated temperature, to improve peak shape, to increase volatility, to improve separation

Purpose of Internal Validation (DNA)

to show the reliability of the technique as practiced by that laboratory

Comparison of assay results and/or impure profiles of the new procedure ...

to that of a validated method can be used to show specificity. Ex. peak purity tests using chromatographic or spectroscopic tech may be useful to show that the analyte peak is not attributable to more than one component.

Problem Prints

too dry or wet, deformed hands, light pressure or rubbing the fingers to increase blood flow and "plump" the fingers may help the print

Tool Impression

tool is compressed into the surface of an object, negative impression

Striation Marks

tool is moved across a surface with pressure, sliding or scraping action

3rd layer of paint

topcoat/basecoat/colorcoat

Gas Cylinders Storage

tored outside the laboratory when not in use. Cylinders must be stored upright with their valve protection caps on and secured to wall

Going from low RI to high RI the light is bent:

toward normal

Griess test

turns dark blue for nitrite residues

Sodium Rhodizonate Test

turns dark red for lead

Wavelength Selector- Prism Monochromators

two faces that refract impinging light giving angular dispersion of the radiation, provides greater radiation dispersion at shorter wavelengths than longer ones.

Crossed Polars

two polarizing filters are placed at 90 degrees to each other causing no light to pass through

Not Ionizing Radiation

ultraviolet, infrared, visible, sound or radio souces

Gun Shot Residues (GSR)

unburned and partially burned partially of gunpowder and primer are propelled out of the barrel and can be deposited on the hands of the shooter as well as object and persons up to several feet away

Methods to Establish Accuracy

use a reference standard of a known concentration or inferred from precision, linearity, and specificity data -minimum of 9 determinations over a minimum of 3 concentration levels Applies to the analytical method and the instrument

Sequential Processing is:

use of two or more methods in a sequence of processing techniques

Ardrox Fluorescent Dye

used for cyanoacrylate-developed latent prints, illuminates with UV lamp, allowing weakly developed latent prints to be seen and photographed

Sticky Side Powder

used for latent prints on sticky-side of adhesive tapes and labels

Regular, nonmagnetic powder

used for processing prints on windows, countertops, television sets, metal file cabinets, painted doors, mirrors, broken glass, and metal window frames

Water Tank

used for test fires as the tank slows the bullet's flight with no damage or distortion to the bullet and the impressions it carries

Substrate (IA)

used in some immunoassays to react with the molecular label and visualize the antibody-antigen pairing by changing the color of the solution

Henry Faulds

used latent prints from a crime scene to identify a burglar

Ninhydrin

used on porous surfaces (paper, cardboard, and wood), reacts with amino acids common in latent prints to forma purple compound

Iodine Fuming

used on surfaces that dusting is impractical, most paper and hard smooth surfaces give a high quality latent print, need to photograph immediately

Scanning Electron Microscopy - Energy Dispersive X-ray(SEM-EDS)

used to characterize morphology and elemental composition of paint samples

Plain Impressions

used to verify the order of the rolled impressions and show characteristics that are sometimes distorted in rolled prints

Advantages of X-ray Detection

useful on difficult surfaces like, multicolored paper, fabric, wood, rubber, leather, and human skin

Forensic Odontology

uses dental records to aid in human identification, used for unrecognizable bodies after a mass disaster and in the identification and comparison of bite marks

Properties of Cellulose (TLC)

uses partition process for separation, 50um spherical particles optimal, run slower than silica plates of same thickness

Tandem Mass Spectrometry

using different mass analyzers in a row, common triple quadrupole, also have Q-TOF

Identifying asbestos fibers

using polarized light microscopy, SEM-EDS, XRD, IR

Test Firing

using the suspect weapon to produce a bullet to compare to the crime scene bullet

Shotgun pellets

usually lead spheres, sometimes steel, bismuth or tungsten, classified by number sizes

Vacuum Sweeping

vacuum cleaner with a filter trap is used to recover trace evidence from an item or area

Establishing Precision

validation of tests for assay and for quantitative determination of impurities, std deviation, coefficient of variation, confidence interval replicate analysis of control samples is generally performed on the same day and over at least 2 weeks expressed as the relative std deviation of the intraday and interday replicate analysis for each control sample.

Heteroscedasicity

variance of measured residuals is heterogeneous and not uniform across the calibration curve, varying with concentration

Homoscedasticity

variance of measured residuals is homogenous or uniform across the calibration curve, randomly distributed near the zero line

Validation

verification, where the specified requirements are adequate for an intended use

1st step of Paint Analysis

visual and macroscopical evaluation, using stereomicroscope description, and documentation of the original condition of the sample

Smooth, non-porous surface recommended sequence:

visual examination using necessary and oblique lighting, examination with specialized light source, cyanoacrylate fuming, dust with powders or dye stains, light source if necessary

Function of Colorcoat

visual finish of the vehicle, color

Comparison microscopy of fibers

visual responses from the two samples must be approximately the same color, brightness and clarity

Naturally occuring glass...

volcanic material obsidian

Heroin paraphernalia analyzed at the lab:

washed out with methanol then analyzed for opiates

Factors affecting depth of penetration (ATR)

wavenumber of the radiation, RI of the crystal, angle of incidence, ratio of RIs between the sample and crystal

Elutropic Series

way to determine solvent strength by starting with least polar,hexane, moving to the most polar of methanol and water

Disadvantages to Raman

weak signal inhibited when analyzing naturally fluorescent substances mixtures are difficult to analyze

Properties of Silica Gel

weakly acidic, very popular due to hardness and resilience

Fully Automatic Weapons

weapon will continue to fire as long as the trigger is depressed and ammunition in the magazine

Factors that affect the amount of time the prints remain:

weather, air currents, humidity, print is made of sebaceous oils or mostly sweat/water, substrate is porous or non-porous

Factors that can affect DR measurements on microspec

weathering, abrasion, contamination, and texture

Elemental analysis of glass could be done by:

wet chemical analysis, neutron activation, atomic absorption, mass spectrography, and emission spectrography techniques

When forensic samples are acquired for testing, certain features must be recorded. Which parameters are important to note when recording details about the evidence?

wet or dry weight of the sample, any colors or odors, nature of the substance, number of packages or units of the substance

Conditioning the Column Entails

wetting the sorbent by passing solvents like methanol, acetonitrile and isopropanol to create an environment to create reproducible retention of the isolate.

Interlaboratory transfer

when a sample is transferred to another laboratory facility it must accompanied by the original chain of custody info and any other info such as sample prep

Matrix-matched calibrations

when calibrations standards can be prepared in the appropriate matrix extract to provide a more accurate cailibration, but do not create the calibration curve with these, commonly used for pesticide residues, can be cost prohibative validity of the matrix used can be checked by adding a known qty of analyte to the sample extract and comparing the increase in detector response with the response produced by the matrix other issues that may arise--- 1. analyte is naturally present in all samples and only in levels higher than occur naturally are relevant ex. Br in celery 2. the analyte is of natural origin and detectable in most or all samples. ex. cabbage having CS2 3. the analyte is detectable in most, if not all samples but does not occur naturally ex. imazailil occurs post harvest in most citrus fruits 4. Background is due to an interfering natural or synthetic chemical aside from the analyte and is present in most samples. A more specific detection method should be used. Confirm residues with greater LCL (lowest calibration level) 5. In GC analysis matix-matching of calibration soltns and priming or conditioning are required

The evidentiary value of glass is maximized...

when it can be individualized to a single source

How to sequence impacts on a glass pane?

when later impacts encounter cracks made previously their cracks will end at the previously made crack

When can glass be individualized to a single source?

when the glass can be physically fitted back together

Inceptive

whether an offence has occurred Ex: controlled substance analysis and alcohol testing

Diode Array Detectors (DAD)

white light onto the flow cell then to a diffraction grating causing the light to disperse into a linear series consisting of hundreds of photodiodes, converted into an electrical signal, detects can report the absorbance that occurred

Using too much pressure to powder the print will do what?

wipe away the print

How to applied powder to print?

with little amount of powder with light twirling and dabbing motions

Types of natural fibers

wool, mohair, furs, cotton, linen and hemp

The three parts of the writing process that can yield useful information are

writing surface (Paper), writing instrument (Pen), and transfer medium (ink)

Is direction of impact able to be determine on glass fractures?

yes, due to the elasticity of glass, the first cracks are form on the opposite of the point of impact due to glass bending with the force of impact