FRNSC 410 Midterm I Notes

accreditation orgs

ANSI-ASQ ANAB: American National Standards Institute-American Society of Quality National Accreditation Board --> crime scene accreditation & forensic lab accreditation A2LA: American Association for Laboratory Accreditation---> forensic inspection (crime scene) accreditation and forensic laboratory accreditation ASCLAD/LAB: American Society of Crime Laboratory Directors/Laboratory Accreditation Board--> crime scene and forensic laboratory accreditation

Reconstruction (defined by Inman and Rudin)

Final step of examination. The ordering of events in relative space and time based on the physical evidence -Event: interaction of 2 or more objects -Incident: sum total of events that comprise activity under investigation Reconstructions must be performed by competent criminalists

philosophies of science

-Justificationism: Hypotheses cannot be conclusively proven but probability can be raised by enough successful predictions; no finite body of evidence can rule out possibility of discovering an exception--> flawed -Falsificationism: If prediction or hypothesis fails, it is rejected. logic can only indicate that either hypothesis or one or more auxiliary assumptions about test situation are false--> flawed

Categorize tearing:

-Tear: technically one form of shear -shear: type of fraction -fracture: separation of object or material into pieces under action of stress (force per unit area)

UV Illumination Methods

-UV-VIS photoluminescence -UV-UV photoluminescence -UV reflection -Human eyes can't pick up UV--> Results (in UV range) must be captured with photography or videography -UV light = energetic radiation; Can cause significant eye and skin damage; Short-λ UV more energetic than long-λ UV -Quartz optical components required-->Glass absorbs significant amount of UV -Must be performed in darkness for maximum visibility

ETHICAL ISSUES

-Unable to document patterns -Exaggerated conclusions -Testifying outside his area of expertise -Evidence fabrication

initial walk-through

-access context of scene -design investigative approach (photos, notes, sketches)

scene investigation team composition

-assess need for forensic specialists -ensure continuation of entry/exit documentation and scene security -select qualified personnel to perform specialized tasks (search, photography, sketches, prints, enhancement, evidence collection) -document team members and assignments

conduct "walk through"

-avoid scene contamination; use established entry path -identify and protect fragile or perishable evidence: ensure all evidence that may be compromised is immediately documented, photographed, and collected -consider alt. hypothesis

transfer of scene control

-brief investigators taking charge -assist in controlling scene -turn over responsibility for documentation of entry and exit -remain until relieved of duty

contamination control

-limit access to people directly involved in processing -identify 1st responders and collect "elimination" samples as necessary -use personal protective equipment to prevent contamination of personnel to minimize contamination -sanitize/dispose tools/equipment and personal protective wear between evidence collection and scenes -identify appropriate place for personal hygience

scene limitations

-location and size of search area -physical barriers -time constraints -personnel -environment (weather) -media personnel (journalist)

document actions and observations

-location of people, objects, and appearance upon arrival (conditions upon arrival such as lights on, doors/windows open, weather) -personal info and statements or comments from witnesses, victims, and suspects -actions (self and others)

Fracture at different levels

-macroscopic -material microstructure -molecular -atomic

consent to search

-must be given voluntarily by someone with authority -3rd part consent: someone who has unrestricted access to property -apparent consent: investigators believe person has proper authority -implied consent: person "gives" consent through reporting of crime

Forensic Science

Application of science (knowledge and methods) to matters of the law (criminal and/or civil). Is a specialist (Forensic: toxicologist, entomologist, chemist, DNA analyst/molecular biologist, toxicologist, questioned document examiner, firearms identification expert, latent print technician).

General Guidelines: Packaging

-must contain initials, case #, date, and other relevant info (sample type, location, etc) -do not package biologic evidence in plastic -seal packaging with tape and initial and date -items must be packaged safely (puncture resistant containers for sharp objects) -samples must be packaged and sealed to ensure no loss or deleterious changes occurs -transport to lab ASAP

initial response

-note/log dispatch info -be aware of people/vehicles entering & leaving scene -approach scene w/ caution, scan area thoroughly & note any areas where activity related to incident may have occurred -assess safety issues before proceeding (look, listen, smell) -assume crime may be ongoing (remain alert and attentive until verification incident had concluded; treat area as crime scene until assessed and determined otherwise)

aims of scene search

-obtain overview of scene -estimate magnitude of crime -document location of physical evidence -establish associations -collect and preserve relevant physical evidence -undertake process of reconstruction -frame relevant scientific questions

evidence log

-record collection in evidence collection log (sample ID, sample type, location of sample, collection method, time of collection) -custody transfer (name/signature of individual receiving evidence, date/time of transfer)

Smooth-Bore Barrel Bore Diameter

Bore diameter expressed as gauge (Number of balls produced from one pound of lead) -Bore diameter equivalent to one ball Example: 12 gauge - One pound of lead produces 12 balls of equal size - Diameter of one ball equivalent to bore diameter of 12 gauge

Essential Wavelengths

Central λ= 415nm: Applications--> bloodstains, semen stains, GSR, fibers, lubricants Central λ= 450nm: Applications--> fingermark luminescence, general search (luminescence), semen stains, GSR, fibers, lubricants

Forensics

Colloquialism; reduces the value of the phrase "forensic science". Forensics does not = Forensic Science

bloodstain patterns

Contact transfers: pattern impressions and hand and fingerprints Non-contact transfer patterns: droplet stains and patterns of dispersed blood droplet stains

Entire Item

Cover (protect) entire surface of item with clean paper to prevent loss of adherent material prior to packaging

What professional skills do employers look at when hiring?

Critical thinking, decision making, good laboratory practices, awareness of laboratory safety, observation and attention to detail, computer proficiency, interpersonal skills, public speaking, oral and written communication, time management, prioritization of tasks.

Why are direct physical fits possible?

Division process creates unique characteristics at boundaries. Boundary roughness occurs randomly and naturally. Boundaries are not completely complementary due to alteration of both surfaces (loss of material)

What personal characteristics do employers look at when hiring?

Drug test, drug history, criminal history, personal associations, polygraph examination, driving record, past work experience, credit history, and a medical/physical examination.

Clip vs Magazine

A clip is a device that is used to store multiple rounds of ammunition together as a unit, ready for insertion into the magazine or cylinder of a firearm. Magazine: detachable box Clip: -stripper clips -moon clips (full and half)

Reality/Practicality according to Inman and Rudin

"At some subjective point, most qualified authorities would agree that, for practical applications, the likelihood that the hypothesis is untrue is so small that it can be ignored" -Subjective: humans are subjective -Most: not all agree -Authority: scientist who has studied material extensively -Small: no absolute answers...likelihood ratios may help -Practical applications: forensic science an applied science

Principle of Divisible Matter

(Inman and Rudin 2001) -Fracture: matter divides into smaller component parts when sufficient force is applied. The component parts will acquire characteristics created by the process of division itself. -Properties useful for source determination: component parts retain characteristics of larger piece (Physiochemical and things like patterns) -properties that may hinder source determination: with time, component parts change, thus making it harder to identify or individualize

Locard Exchange Principle

(Locard) when 2 objects come into contact, there is a cross-transfer of traces of material. he was talking about how you can't solely rely on fingerprints

Light

Visible: 400 -700nm R(620-750) O(590-620) Y(570-590) G(495-590) B(450-495) V(380-450) UV: 10-400nm UVA(315-400) (lowest energy) UVB(280-315) UVC(180-280) (highest energy) Near (long wavelength)--> 300-400nm (lowest energy) mid (short wavelength)--> 200-300nm Far--> 122-200nm (highest energy) IR: 700-1x10^6nm near--> 770-1440nm far--> 1.4- 1000um

quality control

specific methods of implementation of QA guidelines. includes items such as instrument maintenance, reagent prep, and proper usage of standards and controls

CSI: Specialized expertise requested should be in charge of:

dealing with deceased person cases; medicolegal investigators; pathology

evidence photography

ensure adequate midrange and close-up photographs taken prior to collection--> scales in same plane as subject; photographs w/ and w/o scales

Individualization

illustration of uniqueness of object, different from all others, due to distinctive features. Source reduction: Sift through all of the potential sources and remove all class characteristics to get the random characteristics that lead to individualization.

UV reflection

Method: -Illumination of target with UV (NEAR or MID) -Observation of reflected UV (same as incident light) -Camera (photographic or video) must have barrier filter over lens (transmits only excitation λ's) Only reflected light recorded: -Barrier filter must block photoluminescence

Swabs

Moistened: useful for dried blood/other physiological stains Dry: useful for wet blood stains/other physiological stains Collection requirements: (sterile) -swabs -gloves -envelope (PAPER ALWAYS) -pipette -DI water -tape NEVER USE PLASTIC FOR BIOLOGICAL EVIDENCE Tips: -change gloves between samples -collect entire stain if possible (use mult. swabs) -dry swabs before packaging -individual stains cannot be combined (use separate swabs) -always seal packages w/ tape

rifling pattern

look at direction/flow of the land (the raised parts) when looking into the bore

defined scene techniques pros and cons

pros: -minimization of errors -enhance evidence recognition -limits unguided searches cons: -mechanical process -non-scientific (limits scientific thought)

Scraping

sample dry/flaking; sample large Collection requirements (Sterile): -gloves -disposable razor -envelope or druggist fold -tape

Evidence Packaging

Paper/Cardboard: -bags -evidence -druggist fold -boxes Plastic: -bags -vials -jars Glass: -vials -jars Metal: -tins (non-biological evidence in sufficient quantity) -paint cans (fire debris and explosive residues)

Ultimate Aims of Forensic Science:

Solve crime by: -verify a crime -establish modus operandi (MO) -ID of persons responsible -exonerate innocent individuals considered suspects

first responders

usually the only personnel to view the scene in pristine condition (more personnel enter scene, increasingly altered)

Flow Forming

•Round barrel preform drilled and reamed -Hole size > desired bore diameter •Mandrel inserted into barrel preform -Mandrel contains negative impression of lands and grooves •Barrel preform pressed and elongated over mandrel •Simultaneously rifles barrel with reduction to desired bore diameter

Button Rifling (Swaging)

•Round steel bar drilled and reamed -Hole size < desired bore diameter •Grooves pressed into barrel with rifling button -Button forced through barrel -Button contains negative impression of lands and grooves •Simultaneously rifles barrel with expansion to desired bore diameter

evidence integrity and control

--collect each item identified as evidence -establish chain of custody -obtain standard/reference samples -obtain control samples -obtain elimination samples as necessary -secure electronically recorded evidence from vicinity -identify and secure evidence in appropriate containers -package items to avoid contamination and cross-contamination -document condition of firearms and other weapons prior to rendering safe for transportation and submission -avoid excessive handling of evidence after collection -maintain evidence to minimize loss or degradation transport and submit evidence for secure storage

sights

-Aperture Sights (looking through a hole when aiming) -Telescopic Sights (cross-hairs) -Holographic Sights (red dot when aiming) -LASER Sights (on actual target)

Complications in Physical Evidence Record

-Artifacts: something observed in a scientific investigation or experiment that is not naturally present but occurs as a result of the preparative or investigative procedure; Post-incident interactions may complicate or "overwrite" physical evidence record (alter evidence; reposition evidence; obscure evidence; obliterate evidence; create "evidence"/contamination) -scene must be "frozen" promptly by investigators

Methods to understand and describe world:

-Identification of patterns (spatial and temporal) to establish general rules--> inductive reasoning -Prediction of occurrences in specific examples using general rules--> deductive reasoning

Types of Luminescence

-Bioluminescence = resulting from biological processes -Chemiluminescence = resulting from chemical processes -Crystalloluminescence = resulting from crystallization -Electroluminescence = resulting from application of electric current -Photoluminescence = resulting from absorption of light (Ex:Fluorescence; Phosphorescence) -Thermoluminescence = resulting from absorption of light followed by re-heating of material -Radioluminescence = resulting from impingement of ionizing radiation

Falsifiability:

-Can never prove hypotheses true (can only fail to prove false; accepted as true until proven otherwise) -scientists vigorously attempt to disprove null hypothesis (OG hypothesis)--> if null hypothesis cannot be disprove, may be true; if null hypothesis disproved, alternative hypotheses must be considered

Division Process

-Direct and Indirect Physical Fit -Physiochemical Properties--> physical properties (density, color, reflective index, etc) and chemical composition

Luminescence

-Emission of light at low temperature--> From object that has NOT been heated -NOT incandescence (light generation at high temperature)--> From object that has been heated

Immediate Aims of Forensic Science:

-Establish key elements of incident (preliminary reconstruction) -Provide investigative leads (Victims & perpetrators) & possible links to other crimes -associative and corroborative evidence (physical and circumstantial) -confirm statements from victims, suspects, and witnesses

exclusionary rule:

-Evidence obtained in violation of 4th amendment will be suppressed (protects you from illegal search and seizure being included in court)

Photoluminescence Method

-Excite target with select λ (typically UV or VIS) -Observe emission of light with barrier filter-->Barrier filter must not transmit any excitation λ's -Object appears lighter on darker background -Should be done in near or complete darkness!--> Emission typically weak

QA

-Goals and objectives: clearly defined and appropriate -organization and management: appropriate organizational scheme; well-defined management, supervisory, and scientist/technician levels -personnel: appropriate and continuing education and training; adequate staffing for 24/7 operation w/ expected case load -facilities: climate controlled w/ adequate space for seating and work; secure space for off-site investigation/processing and storage (vehicles) -evidence control: climate controlled, secure space for storage of records and evidence -validation: equipment and protocols -reports and review: standard format w/ appropriate language and terminology; reconstruction vs procedural report; peer review of work and work products (report); technical vs administrative review -proficiency testing: yearly or bi-yearly testing of staff -corrective action: necessary for addressing problems -outsourcing (consultation): process to engage outside specialists -accreditation: assessment and sanctioning of organization/unit; audits (internal "in-house" vs external performed by accrediting organization) -certification: assessment and sanctioning of individuals

MORAL IMAGINATION SENSES/CATEGORIES

-Harm -Fairness -Loyalty to "in-group" -Respect for authority and hierarchy -Purity/sanctity

Post-Incident Interactions (Creation of Artifacts)

-Human Activity: -People: persons discovering scene; responding personnel (police, fire, and emergency medical service activities; investigative personnel (police, medical examiner/coroner, attorneys) -Activities: removal (cleaning), alteration, re-positioning, and obfuscation of evidentiary material; contamination (secondary transfer of material; evidence co-mingling, poor packaging, etc) -Animal and insect activity: fly spots, roach trails, removal of material, secondary transfer of evidence, etc. -Natural activity: weather and other environmental concerns; decomposition

Polarized Light and the Human Eye

-Human eye cannot differentiate randomly oriented light from polarized light -Polarized light only detected by intensity or color effect, e.g., reduction of glare when wearing polarizing sunglasses

Evidence Authenitcation

-Identification of object offered (authentication) -establish condition of object

diffuse reflection

-Light impinges upon rough surface -Light reflected (scattered) in random directions Diffuse Reflection Method: -Rough object on flat, shiny surface or dark surface--> Illuminate target (illumination angle approximately 45°) --> More obliquely angled illumination may be required--> ∠incidence --> 90° -Reflected light from object reaches camera -Light striking surface reflected away or absorbed -Perform in darkened environment -Couple with absorption method (complementary color filters), if possible -Subject appears lighter on darker background -Can be used in reverse situation (flat, shiny object or dark object on rough surface) Episcopic Coaxial Illumination Method: -Type of diffuse reflection -Target surface must be flat -Incident light reflected from flat, shiny surface toward camera/viewer -Diffusely reflected light scatters away from camera/viewer -Object appears darker on lighter background

Polarization by Reflection

-Light reflected from flat surfaces often partially polarized -->Electric vectors of reflected light vibrate in plane parallel to surface -Surfaces that commonly reflect polarized light are water, glass, sheet plastics, and highway surfaces--> Many transparent materials are good polarizers (not mirrors!)

Polarized Light

-Most forms of natural and artificial illumination produce light waves whose electric field vectors vibrate perpendicular in all planes with respect to direction of propagation -If electric field vectors restricted to one plane by filtration of beam with specialized materials: Referred to as plane or linearly polarized with respect to direction of propagation; Waves vibrating in single plane termed plane parallel or plane-polarized Creation of Polarized Light: -Reflection -Absorption -Other methods

Codes of Ethics and Conduct

-National organizations: American Academy of Forensic Sciences (AAFS) and American Board of Criminalistics (ABC) -Regional organizations: California Association of Criminalists, Northeastern Association of Forensic Scientists, American Chemical Society

Generation of Random Characteristics

-Nature -Man (Hand-made items are all unique; machine-made items have random characteristics acquired after production (finishing and use)) -Entropy (decline into disorder)--> increasing usage and time change characteristics; objects become unique because each subject to different "local microenvironment"

Ethical Transgressions

-Planting evidence -Collecting evidence without a warrant -Ignoring evidence at a crime scene which may exonerate -Falsifying laboratory examinations: Reporting conclusions for tests not performed ("dry-labbing") and Fabricating scientific opinions based on invalid interpretations -Examining physical evidence when not qualified -Extending expertise -Using unproven methodologies -Overstating an expert opinion by using 'terms of art' unfamiliar to juries -Failing to report a colleague, superior, or subordinate who engages in any of these activities

Additional Considerations of Some Interactions

-Predictable (within limitations): decomposition, insect activity -Unpredictable: human activity -Transient: odors, melting ice or snow, etc.

Production of Physical Evidence Record

-Production Process: Humans present at location; human-initiated interactions occur at location; interactions alter environment and items at location -Alterations: Type and quantity (few to many; inconspicuous to conspicuous); alterations create physical evidence record according to physical laws -Physical evidence record: Incomplete by nature; some aspects are transitory; complicated by post-incident interactions

Warantless Searches

-Public Property -Exigent Circumstances: search for victims and suspects; prevent destruction of evidence or stop crime in progress; protective sweeps; fire department personnel during fire fighting effort -Plain view: evidence observed in "plain view" can be seized -Open fields: evidence observed on property outside curtilage of residence can be seized

Physical Transfer

-Requires 3 objects and energy -Objects -original source -fragments from source (S) (Macro or microscopic) -target surface (T) for fragments -energy facilitates transfer from S to T -Direct contact -no contact

legal Issues

-Search and seizure -Brady v. Maryland (Brady Rule): requires prosecutors to disclose materially exculpatory evidence in government's possession to defense; evidence that may negate defendant's guilt, reduce defendant's potential sentence, or question credibility of witnesses -evidence authentication (chain of custody)

prioritize collection of evidence

-conduct careful and methodical evaluation considering all possibilities -focus on accessible areas in view and proceed to out of view locations -select systematic search pattern for evidence collection based upon size and location of scenes -select progression of processing/collection methods so initial techniques do not compromise subsequent processing/collection methods: most transient evidence to least transient forms; move from least intrusive to most intrusive processing/collection methods -continually assess environmental and other factors that may affect evidence -be aware of possibility of multiple scenes

control people at scene

-control all individuals to prevent contamination, alteration, or destruction of physical evidence -exclude all nonessential and unauthorized personnel (challenging but critical)

scene assessment

-determine number and size of scenes and prioritize -estab secure area for equipment and consultation -communicate w/ personnel at different scenes, if applicable -request additional investigative resources, if needed -identify potential witnesses and obtain valid IDs -ensure surrounding area canvassed and results documented -ensure preliminary documentation and photography of scene, injured persons, and vehicles

final scene survey

-each area of scene visually inspected -account for all evidence collected -removal of all equipment, supplies, and generate material (trash) -dangerous material and conditions reported and addressed -scene released in accordance w/ jurisdictional requirements

scene safety

-ensure no immediate threat to scene responders: assess whether specialized response teams are required (fire dep, ems, hazmat) -assess scene for dangerous persons and notify police if necessary

scene debriefing team

-estab debriefing team, which includes investigator(s) in charge, other investigators, evidence collection personnel, and initial 1st responding officers, if available -debrief all team members for input --discuss preliminary findings, potential forensic analyses, and analytical sequence -initiate any actions identified in discussion to complete scene investigation -identify additional resources needed (statements from witnesses, autopsy report) -brief persons in charge upon completion of assigned scene tasks -estab post-scene responsibilities for law enforcement personnel and other responders

scene boundaries

-establish boundaries, from focal point extending outward to include location of incident, potential points where victim and evidence may have been removed, locations where victim and evidence may have been moved -set up physical boundaries or use existing boundaries -once boundaries estab, document all people entering and leaving -document original location of victims or objects that are moved -ensure warrant obtained, if necessary, prior to search and evidence collection

Reconstruction Limitations

-expectation and bias -over-interpretation -reconstruction vs reenactment

Factors affecting transfer, detection, and analysis:

-force and ease of fragmentation (determines number and size of fragments) -force of transfer and properties of source and target (ability of source to retain fragment; ability of target to accept fragment (dependent on transfer force) -secondary transfer (fragment transferred from A (source) to B (primary target) to C (secondary target)--> may lead to erroneous conclusion A contacted C -unrelated transfer: fragments may transfer before and after incident that are unrelated to incident (crime)

CSI Unit Quality issues

-goals and objectives -orgqanization and management -personnel -facilities -evidence control -validation (equipment; protocols) -analytical procedures -equipment calibration and maintenance -reports and review -proficiency testing -corrective action -safety -outsourcing (consultation) -audits and accreditation (internal and external) -certification

emergency care

-guide medical personnel to injured persons to minimize contamination of scene -document actions of medical personnel at scene and instruct to avoid or minimize contact w/ potential evidence -instruct medical personnel not to clean up scene or remove/alter items -obtain appropriate contact info for all responding medical personnel (so that you can make separate their prints etc from actual scene)

post-scene interactions

-human activity (person discovering scene, responding personnel, investigative personnel, removal of evidentiary material, secondary transfer of evidence) -animal and insect activity -natural activity (weather, decomposition) -differential spread of blood through fabric blends

hallmarks of a pseudo-scientist

-impenetrability (refusal to consider other alternative hypotheses; cognitive bias--> confirmation bias and congruence bias (testing of hypothesis w/o considering alternate hypothesis)) -ulterior motives ($$, recognition) -lack of formal education and training (bandwagoning) -bunker mentality (confirmation results in claims of persecution and defamation)

scene characterization

-incident ID (burglary, homicide, etc) -adherence to single hypothesis -scientific v unscientific approach (object v subjective)

General Guideline: Marking and Labeling

-label samples with unique identifier and photograph prior to collection -use labeling system that accounts for multiple items

documentation

-review scene assessment to determine type and amount of documentation needed -coordinate photographs, videos, sketches, measurements, and notes -photograph scene: establishing, midrange, and close-up coverage; physical evidence, w/ and w/o measurement scales and evidence identifiers; victims, suspect, witnesses, crowd, and vehicles; additional perspectives (aerial, area under body) -prepare preliminary (rough) sketches and measure: immediate area; record case number and indicate north; relative location of evidence; correlate evidence w/ records; evidence prior to movement; rooms, furniture, or other objects; distance to adjacent buildings or other landmarks -generate note: document location, time of arrival, and time of departure; describe scene as observed; record transient evidence (smells, sounds, sights) and conditions (temp, weather); document departures/deviations from usual procedures and protocols

Phosphorescence

-type of photoluminescence -Excitation with select λ (typically UV or VIS) -Emission of light at longer λ -Emission CONTINUES AFTER excitation ceases -glow in the dark; taken place in organisms, solutions, molecules

Fluorescence

-type of photoluminescence -Excitation with select λ (typically UV or VIS) -Emission of light at longer λ -Emission occurs ONLY DURING excitation -taking place in atoms or molecules

Ideal Physical Evidence Properties: CHaracteristics

-uniqueness -permanence (persistence over time) -transfer (reproductibility and sufficient quantity)--> divisible matter and impression evidence -ability to recognize and observe

Evidence Types

1) Blood and other physiological specimens 2) fingermarks 3) trace evidence (hair, fibers, glass, paint, etc) 4) impression evidence (footwear, footprint, tire tracks, etc) 5) Gunshot/Firearm Discharge Residue 6) Soil 7) Other Evidence (Projectiles, firearms, fire debris, bombs/IEDs, electronic evidence, entomological evidence)

Scientific Method

1) Problem Identification 2) Data Collection 3) Hypothesis Formation 4) Hypothesis Evaluation (or back to 2 w/ feedback loop) 5) Formation of Conclusion

7-STEP Analysis

1) State perceived problem(s)--> overstated conclusions 2) Check facts--> No photographic documentation of observations; Testified as follows: "Indeed, and without a doubt", Error rate of "Something less than my savior, Jesus Christ" 3) Identify relevant issues 4) Values, codes (professional orgs: American Dental Association, etc), laws, stakeholders, etc. 5) Develop list of options: Overstate conclusions; State conservative conclusions; Be noncommittal or state inconclusive findings; Do not get involved 6) Use moral imagination and consider each option--> Consequences, relevant rights/duties, etc.: 7) Choose best option (State conclusions within bounds of profession and science)--> What can be done in the future to avoid problem? (Know limitations of science and techniques; Know limitations of personal knowledge, skills, and abilities; Receive adequate and appropriate training; Remain within area(s) of expertise; Remain current with science and literature; Seek true peer review-->Other colleagues and scientists)

Potential Pitfalls when CSI is controlled by the police:

1) Wide range of expertise already required--> lack of scientific background 2) Potential for bias--> police investigating a police-involved incident 3) control issues--> CSI tends to be controlled by law enforecement

Collection Techniques

1) entire item 2) Swab (moisten vs dry) 3) cutting 4) scraping 5) brushing 6) forceps (tweezers): hand-picking 7) Adhesive Methods (Gelatin lifters, adhesive tape, SEM stubs) 8) electrostatic lifter 9) vacuum

High-Intensity, Tunable-Wavelength Light Source (HITWLS)--> AKA Forensic Light Source (FLS) AKA Alternate Light Source (ALS)

Advantages: -Flexibility -Lower cost -Should produce intense, narrow bandwidth at wavelength of interest. Disadvantages: -Lower intensity than LASER Components: •Lamp - Intense, white illumination source -Xenon arc lamp commonly used -Should produce wavelengths from UV to VIS • Cold mirror -Transmits UV and VIS -Blocks IR •Bandpass filter -Interference filter that permits "tuning" of wavelength -Higher purity, i.e. narrow bandwidth, results in decreased transmission •Collimation lens -Focuses light onto light guide entrance •Light guide -Single-core liquid (higher transmittance than fiber optic bundles) -Fiber optic bundles (Less common) • Focusing lens -Provides uniform illumination with sharp edges -Must permit range changes (spot size) from distant to close-up illumination

Association (defined by Inman and Rudin)

An inference of contact between 2 objects, the source of the evidence, and the target on which it was found

Specular reflection

Angle of reflection = angle of incidence

What can be evidence?

Anything and everything

Glasses/Barrier Filters

Excitation Wavelengths (nm) --> Color of glasses/filter 400-420---->clear 450-480---->yellow 490-520---->yellow or orange 530-570---->orange 580-650---->red

Certification Orgs

IAI: International Association for Identification -Certified Crime Scene Investigator: min of 1 yr -Certified Crime Scene Analyst: min of 3yrs -Certified Senior Crime Scene Analyst: min of 6yrs -Certified Crime Scene Reconstructionist -Bloodstain Pattern Analyst -Forensic Analyst -Forensic Photography ABC: American Board of Criminalistics -Diplomate (D-ABC): BS/BA in a natural science, 2yrs of forensic laboratory or teaching experience, and successful completion of ABC examination -Fellow (F-ABC): successful performance on a proficiency test and minimum of 2yrs experience in specialty area -Affiliate: successful completion of certification examination but w/o 2yrs work experience

scene techniques

Indoor: -zone (sector) -point to point outdoor: -line/strip -grid

Individuality Principle

Kirk

LASER

Light Amplification by Stimulated Emission of Radiation Advantages: -High intensity -Defined operational wavelengths (monochromatic) Disadvantages: -Limited flexibility (few wavelengths for most lasers) -High cost

VIS-VIS photoluminescence

Method -Illumination of target with VIS -Observation of luminescence emission of VIS May be used to locate: -Luminescent targets -Non-luminescent targets (absorb VIS light, i.e., blood) on luminescent backgrounds

UV-UV photoluminescence

Method: -Illumination of target with MID-UV -Observation of luminescence emission (NEAR-UV) -Camera (photographic or video) must have barrier filter over lens (transmits only long-wavelength UV) Many biological fluids luminesce under short-λ UV irradiation Long-λ UV emission weak and difficult to record

UV-VIS photoluminescence

Method: -Illumination of target with UV (NEAR or MID) -Observation of luminescence emission of VIS Simplest of UV illumination techniques: -Observation of VIS light emission May be used to locate: -Luminescent targets -Non-luminescent targets (absorb UV light, i.e., blood) on luminescent backgrounds

Absence of evidence is not evidence of absence.

No evidence indicates individual not perpetrator

Who should investigate crime/incident scenes?

Police Personnel (experience scene investigators), Forensic Scientists (competent scientists), Criminalists (experience scene investigators and competent scientists).

Polarization by Absorption

Polyvinyl alcohol-iodine complex polarizer (modern polarizers) -Light-absorptive linear polyiodide contained within polyvinyl alcohol matrix -Manufacture of Polaroid™ filters: Sheet of polyvinyl alcohol heated and stretched in one direction while softened, which aligns long polymeric molecules in direction of stretch; Sheet impregnated with iodine or similar dichroic dye; Iodine atoms attach to aligned polymeric chains; Iodine atoms provide electrons, which can move easily along aligned chains, but not perpendicular to them; Light waves with electric fields parallel to chains strongly absorbed because of dissipative effects of electron motion in chains. -Light vibrating parallel to polymer chains is absorbed -Light vibrating perpendicular to chains is transmitted

Criminalist

Recognizes, identifies, individualizes, and evaluates physical evidence using the methods of the natural sciences in matters of legal significance. Includes the reconstruction of of events based on physical evidence analysis. Is a generalist (familiar in many disciplines within forensic science; may specialize in one or many areas).

Firearm Barrels

Rifled Barrel: has lands and grooves Smooth Bore: no lands or grooves (smooth)

Ballistics

Science and study of projectiles. Primarily a concern in reconstruction of shooting incidents 4 Types: •Interior ballistics: Study of projectile behavior from propellant ignition to barrel exit •Transitional (intermediate) ballistics: Study of projectile behavior from barrel exit to point where pressure behind projectile equalized (between interior and exterior ballistics) •Exterior ballistics: Study of projectile behavior from point where pressure behind projectile equalized to target interaction (primary forces acting on projectile = air resistance and gravity) •Terminal ballistics: Study of projectile interaction with target

Direct Physical Fit

Separated pieces juxtaposed and associated (jigsaw fit): separation process random and material malleable to production of random characteristics ex: broken glass

3 modes of Fracture

Tension: Opening (1 part goes up, other goes down) In-plane Shear: tear (1 part goes left, other goes right) Anti-plane Shear: sliding (moving forward in opposite directions)

What is the important & challenging aspect of an investigation?

The scene because common perception of primary goal of forensic science...Linkages between the incident scene, victim, and perpetrator (tool marks, firearm evidence, hair and fiber evidence, trace evidence, fingerprint, impression/imprint evidence, blood and other human physiological fluids)

Spatial Trait Transfer

Types: -Impression evidence (toolmarks, etc) -print or tract evidence (fingerprints, etc) What is transferred? -info (spatial arrangement of features) -possible micro and macro evidence

Identification

classification of objects into groups sharing common features and properties (class properties). "Same". Used differently with police personnel, they have "identification bureaus"

pseudoscience

collection of beliefs or practices mistakenly regarded as being based on scientific method pseudo-scientist: practitioner of pseudoscience

ISO/IEC

greek--> isos= equal International Organization for Standardization IEC: International Electrotechnical Commission 17020:2012: conformity assessment (requirements for the operation of various types of bodies performing inspection 17025:2005(E): general requirements for the competence of testing and calibration laboratories 17043:2010: conformity assessment (general requirements for proficiency testing)

science

intellectual and practical activity encompassing systematic study of the structure and behavior of the physical and natural world through observation and experiment -Methods to understand and describe world: Identification of patterns (spatial and temporal) to establish general rules (Inductive reasoning--> fundamental tool of criminalists) and Prediction of occurrences in specific examples using general rules--> Deductive reasoning -Hypothesis testing defines classical science -Necessary to form hypotheses and means to test them -Scientific method = framework for hypothesis testing

enthusiasm

intense and eager enjoyment, interest, or approval Enthusiast: a person who is highly interested in a particular activity or subject

scientist

person who is studying or has expert knowledge of one or more of the natural or physical sciences

Documentation includes:

photography, videography, notes, and sketches

Use of Polarizing Filters

reduction of glare

reference samples

representative specimens from objects/locations used for comparison to questioned samples (Ex: scalp hair, carpet fibers, soil)

CSI: Criminalists should be in charge of:

scene control; documentation; IDing and handling physical evidence; scientific and reconstructive aspects

CSI: Police should be in charge of:

security of the scene and assisting experienced criminalists w/ scene investigation

Indirect Physical Fit

separated pieces cannot be juxtaposed (elastic material results in distortion, etc); relies on surface or internal characteristics of pieces such as surface patterns/markings, surface contours, etc; ex: plastic bags, cut newspaper

scene case file

should contain: -initial responder's documentation -emergency medical personnel documents -entry/exit documentation -notes, photographs/videos, and crime scene sketched/diagrams -evidence documentation -other responders' documentation -record of consent form or search warrant add relevant reports when available (in reconstructions): -laboratory reports -other technical reports -investigative reports

Ultimate aim of scene investigation and reconstruction:

to answer the 5 w's and h. Not all questions relevant to all scenes and only question science not concerned with is "why"

search warrants

warrant required to search private property

quality assurance

written guidelines that cover all aspects of laboratory from safety to personnel requirements (education, training, etc). includes specific documentation of method reliability (validation)

color wheel

yellow <--> purple green <---> red blue <---> orange UV <----> clear

Amido Black 10B

• Alcohol-based solution: -Staining solution (2 g Amido Black 10B; 900 mL methanol (MeOH) and 100 mL glacial acetic acid (HOAc)) - Destaining solution (900 mL methanol (MeOH) and 100 mL glacial acetic acid (HOAc)) • Aqueous solution -Staining solution (19 g citric acid, anhydrous; 2 g Amido Black 10B; 2 mL Kodak Photo-Flo 600 or equivalent, e.g., 6 mL Kodak Photo-Flo 200-->Dissolve citric acid in 1 L distilled water and add Amido Black 10B; Stir for 30 minutes, add Photo-Flo, and stir lightly) - Destaining solution (38 g citric acid; Dissolve in 2 L distilled water)

Fixation of Biological Stains

• Functions -Preservation (Prevention of decay via autolysis or putrefaction-->Termination of biochemical reactions; Inactivation of proteolytic enzymes AND Protection from extrinsic damage-->Chemical fixatives generally toxic to microorganisms) -Enhancement (Mechanical strength or stability; Preservation of morphology for subsequent analyses) • Types -Heat -Chemical •Cautionary remarks -Creation of artifacts (Fixation always creates artifacts--> Patterns will be slightly altered or destroyed; Caution must be exercised!) -Over-fixing and overheating (May alter stains and create artifacts; May destroy underlying surface via overheating)

Chemical Enhancement: Non-blood (residue) impressions

• Impressions containing Ca, Mg, Fe, Al, and other metals -8-hydroxyquinoline and UV illumination -Potassium or ammonium thiocyanate (Fe only) •Impressions containing CaCO3 -Bromphenol blue •Waxy, oily, fatty, greasy impressions -Iodine fuming -Physical developer •Impressions of wet origin (or muddy impressions) -Cyanoacrylate fuming, fingerprint powders, and UV illumination -1,8-Diazafluoren-9-one (DFO) •Impressions on glass, plastic, and other non-absorbing surfaces -Safranin O •Impressions on metal -Antimony trichloride

Barrel Rifling Methods

• Rarely used methods; -Hook cutter: Cuts one groove at a time -Scrape cutter: Cuts two grooves once -Flow forming •Commonly used methods -Gang broach (cut rifling) -Rifling button -Hammer forging -Electrochemical etching

Broaching

• Round steel bar drilled and reamed -Hole size = desired bore diameter •Grooves cut with gang broach (series of cutting tools on rod) -Forced through barrel with hydraulic pressure •Successive cuttings performed with broaches of increasing size -Stop when desired groove depth attained

Stains and dyes: Blood impressions

•Amido Black 10B -Methanol-based -Water-based •Water-soluble dyes -Patent Blue -Fuchsin Acid -Tartrazine

CrimeScope Usage

•Connect liquid light guide -Two grooves (Large beam/maximum power; Uniform beam for examination/photography) •Set filter wheel to WHITE or CSS •Turn on MAIN power switch -Confirm air circulation from top exhaust ports and circulator fans •Turn on LAMP switch -Lamp should produce output within 1-2 minutes •Use CrimeScope - Scan first with WHITE or CSS •Turn off LAMP switch first! -Allow fans to operate for 3-5 minutes •Turn off MAIN power switch •CAUTIONARY REMARKS -Wear glasses to prevent UV irradiation of eyes! -Do NOT restart lamp when hot!-->Shortens life of lamp and power supply! -"Arcing" noise indicates problem (Early lamp re-ignition; Lamp blown) -Use CrimeScope for at least 20 minutes prior to shutdown to extend lamp life -If power outage occurs, immediately turn off LAMP switch -If lamp fails, it may emit dangerous vapors -Do not turn off instrument -Immediately leave area for 5-10 minutes -Upon return, power down instrument and replace lamp

Sensitivity to IR

•Film -Must procure IR-sensitive film (difficult!) •Digital sensors -Sensitive to NEAR-IR -Many cameras possess IR blocking filter over sensor -May still be sensitive to IR (easy to check!) -Must use IR barrier filter (Permits transmission of IR; Blocks VIS light)

Firearm Evidence

•Firearm types •Manufacture of firearm barrels •Ammunition •Firearm discharge •Examination of firearms, fired bullets, and cartridge casings

Firearm and Range Safety

•Follow all instructions of police officer(s) •Do not bring any guests, including firearms! •Do not touch or handle any firearm until instructed •Do not carelessly handle any firearm •Assume every firearm is loaded •Do not position finger inside trigger guard until ready to discharge firearm •Infractions will NOT be tolerated

Fixing of Bloodstains

•Heat: -Challenging in field -Assists in adhering stains to underlying surface •Chemical: -Frequently used; less challenging -Common fixatives -5-sulfosalicylic acid -20 g 5-sulfosalicylic acid (dihydrate) in 1 L H2O -Fix for 10 min and rinse with H2O for 5 min prior to enhancement -Methanol (MeOH), ethanol (EtOH), acetone) Bloodstains must be fixed prior to enhancement! -Some formulations contain chemical fixatives; thus, fixed during application

IR Illumination

•Illumination λ's > 700 nm •Barrier filter used to block all λ's < 700 nm •Absorption or reflection of IR irradiation by: -Background or subject •Useful for GSR, metallic deposits, questioned documents, etc.

Chemical Enhancement: Blood Impressions

•Leucocrystal Violet (LCV) •Diaminobenzidine (DAB) •Ninhydrin •Luminol •Other catalytic tests for blood (LMG, TMB, o- tolidine, etc.)

Physical Enhancement

•Lifting to surfaces that produce contrast (impressions of dry dust and residue) -Electrostatic -Gelatin and adhesive lifters •Application of powder (impressions of wet origin on non-porous surfaces) -Conventional and magnetic fingerprint powders -Fluorescent fingerprint powders -May be followed by Illumination and photography with filters OR Gelatin or adhesive lifting •Electrostatic detection of indentations (on paper/thin card stock) -Electrostatic Detection Apparatus (ESDA) -Indentation Materializer (IM) -Vacuum Box (VB)

Manufacture of Smooth-Bore Barrels

•Methods -Drilling and reaming of bar stock -Use of seamless metal tubing •Addition of chokes (barrel constrictions) -Different chokes available -Keep pellets grouped tighter over longer distances -Increases effective range

Firearm Types

•Rifled barrels: -Designed to fire one projectile -Types: Pistols (handguns); Rifles; Submachine guns designed for pistol ammunition); Machine guns (designed for rifle ammunition) •Smooth-bore barrels: -Designed to fire multiple projectiles -Types: Shotguns

Bore Diameter and Caliber

•Rifled firearms -Bore diameter (land to land) -Caliber (Designates particular cartridge; Nominal indicator of bore diameter) •Smooth-bore firearms -Gauge (indirect bore diameter)

Electrochemical Etching

•Round steel bar drilled and reamed -Hole size = desired bore diameter •Probe placed into barrel -Metal probe (cathode) has inset plastic strips at end -Only plastic contacts barrel (anode) -Strips are reverse image of lands •Barrel and probe immersed in electrolyte (NaNO3 solution) -Solution circulated under pressure to remove reaction products away from metal probe •Application of voltage to probe etches metal where plastic strips do not contact barrel (rifling grooves) •Etching stopped when desired groove depth attained

Hammer Forging: Produces polygonal rifling!

•Round steel bar drilled and reamed -Hole size > desired bore diameter •Barrel placed over mandrel (cylindrical rod possessing rifling characteristics) •Barrel pressed/hammered around mandrel then removed •Simultaneously rifles barrel with reduction to desired bore diameter

Hammer/Trigger Actions

•Single action only -Hammer must be cocked to discharge firearm •Double action only -Firearm discharged with trigger pull only (Hammer/firing pin cocked during trigger pull) •Single action/double action -Firearm discharged using either mechanism

Rifles

•Single shot •Pump action •Lever action •Bolt action -Turn bolt -Straight pull •Semi-automatic -Blowback -Recoil operated - Short -Long -Gas operated (gas is used to eject cartridge) •Automatic "Assault" rifles maybe automatic or semi-automatic

shotguns

•Single shot •Double barrel -Side-by-side -Over-and-under •Pump action •Lever action •Bolt action •Semi-automatic •Automatic

Pistols

•Single shot (holds only 1 bullet) •Derringers (looks like a revolver w/o the cylinder) •Revolvers (revolving pistols) -break action (top break) revolver -swing-out cylinder revolver •Self-loading (semi-automatic) -Recoil operated (locked breech/bolt and barrel) (Bolt and barrel locked together; Remain locked for some distance after discharge) -Blowback (unlocked breech/bolt and barrel) (Bolt and barrel NOT locked; Held together by recoil spring pressure) •Automatic

Cardinal Firearm Safety Rules

•Treat every firearm as if loaded -Keep muzzle pointed in safe direction until ready to fire -Keep finger off trigger (out of trigger guard) •Firearms should be unloaded during: -Routine handling -Examination -Disassembly -Cleaning •Understand mechanical and handling characteristics of firearms being handled or examined •Other rules regarding hunting and shooting (NRA, etc.)

General HITWLS Remarks

•Use in darkened conditions •Use tables/manufacturer's instructions as guides -Examine evidence using all available λ's -Use excitation color opposite of target color •Dried blood absorbs wide range of wavelengths (UV through IR) and exhibits strong absorption at 415 nm •WHITE and CSS (Crime Scene Search) used for "general" searches •Extensive exposure to short-wavelength UV irradiation may compromise DNA and subsequent analysis