Gardner IAI

Mechanical Fit

"fracture matching" is where an item is damaged and pieces are deposited in the scene. Because the breakage is random it makes it possible to individualize a specific piece to a specific item. p. 26

Methodology employed in bloodstain pattern analysis...The technician:

* Becomes familiar with the entire scene * Identifies the discrete patterns among the various bloodstained surfaces * Categorizes these patterns based on the established taxonomy of bloodstain pattern analysis * Evaluates aspects of directionality and motion in the stain or pattern * Evaluates interrelationships among stains, patterns, and other evidence * Evaluates angles of impact, points of convergence, and areas of origin (if necessary) * Evaluates viable source events to explain the pattern (based on all of the above)

methodolodgy for crime scene investigation from O'Hara:

*Painstaking, comprehensive collection of data *Arrangement and correlation of that data *Definition of issues and investigative questions *Development of a hypothesis along the lines of the available data and subsequent resolution of any hypotheses 8testing of the hypothesis and elimination, when possible, of contradicting hypotheses *Testing of final hypothesis before acceptance

Suggested format for the crime scene report

-introduction -characteristics of the scene -conditions of the scene -environmental conditions -factors pertinent to entry and exit -scene documentation -collection of physical evidence -search for latent prints -additional examinations

On scene examination of latent blood prints:

1. Amindo-black 2. leuco-crystal violet 3. fluorescein (alcohol-based not aqueous) *Never use luminol or aqueous based fluorescein in an attempt to develop latent prints *Wet surface-dry surface then apply techniques above

GSR residue contains trace amounts of 3 primary elements

1. Antimony 2. Barium 3. Lead

6 basic steps to crime scene processing:

1. Assessing 2. Observing 3. Documenting 4. Searching 5. Collecting 6. Analyzing

Three basic on scene fingerprinting techniques:

1. Basic powder techniques (standard and magnetic) 2. Superglue fuming 3. Small particle reagent *Also be experienced in recovering prints from human skin using the adding machine paper technique and in the use of crystal violet solutions on adhesive tape. Also the recongize methods of recovering latent prints at fire scenes

Class differences in human blood

1. Blood type 2. Variations in blood antigens p.29

the most common fire signs found in the fire scene?

1. Char patterns 2. smoke and soot patterns 3. Damage patterns

5 basic search patters:

1. Circle/Spiral 2. Strip/Line 3. Grid 4. Zone 5. Point to Point

Based on specificity, the characteristics presented by all physical evidence can be classified in two categories

1. Class Characteristics-allows the item to be compared with a group. Characteristics that are common to several objects. Best used in eliminating possibilities. i.e. size, color, common manufacturing pattern 2. Individual characteristics-allows the scientist to compare the item with a specific object/person and include/exclude it as originated from it. "unique" resulting from natural variation, damage, or wear. i.e. fingerprint

Steps in Event Analysis

1. Collect Data, Establish Likely events 2. Establish Event segments from the data available 3. Define Associated Event Segments 4. Order and Sequence the Associated Event Segments 5. Audit the Information 6. Determine and Final Order the Events 7. Flow Chart the Overall Incident Based on the Event and Event-Segment Sequence

What can be used to compare trace evidence to know samples

1. Comparison microscope 2. Infrared Spectrometry 3. Automated refractive index sustem 4. Scanning electron microscope

5 basic objectives to achieve the 2 basic police goals:

1. Crime Prevention 2. Crime Repression 3. Regulating non-criminal conduct 4. Provision of services 5. Protection of personal liberty

Variations of view for the crime scene sketch:

1. Cross-Projection or exploded sketch- combines the standard bird's eye view with "laying down" walls to depict evidence on vertical surfaces 2. Elevation sketch-side view of some portion of the scene, typically a wall or similar vertical structure 3. Three dimensional sketch or view p.166

On scene examination of adhesive surface:

1. Crystal violet, alcohol/water technique 2. Sticky side powders (wet surface allow to dry before trying any of the above-techniques)

On Scene examination of rough non porous surfaces:

1. Cyanoacrylate fuming 2. Powders (consider fluorescent for contrast)

On scene examination order for paper:

1. DFO 2. Ninhydrin 3. Silver Nitrate

It is imperative that narrative scene descriptions be:

1. Detailed, with all the pertinent facts and conditions documented 2. Accurate, with few inferences or subjective evaluations included 3. Understandable, i.e. logical and organized

Functional Photograph Method

1. Document the entire scene in situ 2. Photograph transient evidence as soon as possible 3. Document with mid-range and close-up photographs 4. If items are discovered later, document appropriately 5. Create photographs that document examination results 6. Maintain a photo log

Used to examine paint samples

1. Fluorescent microscopy 2. Infrared Spectrometry 3. Gas Chromatography 4. Scanning electron microscope

The composition of the crime scene team is defined by these two approaches:

1. Functional approach- the team leader designates different teams to do different activities (photos, latents, sketching) 2. Area approach- a single team handles all activities associated with processing p.98

Datum point can be set using

1. GPS device 2. Triangulation to evident landmarks in the area 3. By physical location using a metal pipe or rebar (worst case)

Chemical analysis is accomplished through what intrusmentation

1. Gas Chromatography 2. Mass Spectrometry 3. Infrared Specgtrometry

Basic subunits of genes

1. Guanine (G) 2. Crtosine (C) 3. Adenine (A) 4. Thymine (T) G always pairs with C, A always pairs with T

Types of trace evidence

1. Hair 2. Fibers 3. Glass 4. Paints 5. Soil

The formal sketch has 5 basic elements

1. Heading-informs viewer of the purpose 2. Diagram area-the drawing itself 3. Legend-what the labels depict 4. Title block-important info, DR, address, date/time, sketcher 5. Scale and Direction notation-compass direction and if there is a scale of reference used

Total station systems use what tree measurements from a know datum point?

1. Horizantal angle 2. Vertical angle 3. Slope distance

Three measurements used in Polar Coordinates

1. Horizontal angle-a rotation of the sighting instrument from north in the horizontal plane 2. Horizontal distance-is measured as the distance between the datum point and the evidence item 3. Difference in elevation (when recording elevation data)-elevation is measured as the difference in height from the datum point elevation and the evidence.

Recurring photographic problems:

1. Identification problems 2. Orientation problems 3. Confusion problems 4. Incomplete documentation

Ballistics is broken down into three areas of study:

1. Internal or interior ballistics 2. terminal ballistics 3. External or exterior ballistics

3 areas to consider regarding officer safety:

1. Is this a crime in progress and are there suspects on scene? 2. Are there natural hazards present that can inhibit or harm first responders? 3. Are there man-made hazards present that can endanger first responders?

Any good processing method will demand 5 basic ingredients:

1. Knowledge 2. Skills and Knowledge 3. A methodical approach 4. Flexibility 5. A coordinated effort

Improper photograph can be blamed on 2 main areas:

1. Lack of understanding or practice with photograph equipment 2. Lack of understanding of what the photographs are intended to depict p.132

Fingerprints can exist in 3 basic forms:

1. Latent Print 2. Patent Print 3. Plastic Print

3 basic ridge patterns

1. Loops 65% of all patterns 2. Whorls 30% of all patterns 3. Arches 5% of all patterns

To determine angle of impact:

1. Measure the long and short axis of the stain without the tail or scalloping 2. Divide the short axis by the long axis (should be less than 1) 3. Determine the inverse SIN of this number

Search method employed needs to be:

1. Methodical 2. Systematic

Factors to consider regarding the area or search swath that a single searcher is responsible for:

1. Nature of the ground being searched 2. Lighting conditions 3. On-scene environmental conditions 4. Size of the item being searched for

On scene examination of untreated wood:

1. Ninhydrin 2. Powder/brush

Documentation of the scene has 4 key elements:

1. Notes 2. Photographs/video 3. Sketches 4. Reports

Other than wet surfaces, SPR can be effective in what other situations?

1. Oily windows 2. Oxidized metals 3. Galvanized surfaces 4. Salt water sprayed areas

3 basic types of photographs

1. Overall 2. Evidence establishing 3. Evidence close-up

Two issies with the brush and powder techniques:

1. Overpowder a latent print 2. Applying too much pressure when dusting the print

Bloodstain patterns are grouped into two basic categories:

1. Passive stains 2. Dynamic patterns

Two primary field test for the presumptive presence of blood

1. Phenolphthalein 2. Leucomalachite green

In order to produce quality crime scene photographs the technician must control 3 basic aspects of the camera:

1. Physical control-stabalizing the camera when the shutter is released 2. Light- No matter what the light conditions a flash should be employed (fill flash) 3. Focus and Depth of Field- greater depth of field=smaller f-stops

Areas of specific consideration when searching for fingerprints...

1. Points of entry 2. Points of exit 3. Any appropriate surfaces in and around the area where the actual crime was committed

On scene examination of glossy surface paper:

1. Powder/brush 2. Cyanoacrylate

According to Rynearson & Chisum, context of evidence may manifest itself in a number of ways. Name the 5 ways:

1. Predictable effects 2. Unpredictable effects 3. Transitory effects 4. Relational details 5. Functional details

In deciding where to establish an initial perimeter the officer should consider the following:

1. Primary focal points 2. Natural entry and exits points 3. Secondary scenes

Most common mapping methods

1. Rectangular coordinates 2. Triangulation 3. Baseline coordinates 4. Polar coordinates 5. Triangulation or rectangular coordinates on a grid 6. Triangulation on a baseline 7. Total station systems

Debriefing the responding officers: Once the initial responding officer is found he should be interviewed to determine the following:

1. Scene Scope and nature 2. Changes to the scene (i.e. police/fire entry) 3. Status of parties involved 4. Scene Security

The purpose of a debriefing and assessment by the investigative team is to consider the following issues:

1. Scope of the scene 2. Scene integrity and contamination control 3. Team approach and composition 4. Search methods to be used 5. Personal protective measures

When a smooth non porous surface is wet:

1. Seize and dry followed by the usual techniques OR 2. Small particle reagent

When a porous surface is wet:

1. Seize and dry-follow by physical developer

Other processes that may work on non porous smooth surfaces:

1. Silver nitrate may work on some plastics 2. Iodine fuming may be effective on fresh prints other than those located on metal

3 categories of tool marks

1. Striation 2. Compression 3. Saw and drill marks Striation marks are caused by the cutting edge of a tool in contact with/sliding against a target surface. Compression mark is when a tool is forced into a soft material.

Sighting instruments used in Polar Coordinates

1. Surveyor's Transit 2.Laser sighting device 3. Handheld compass (in a worst case)

Two basic goals of police

1. The prevention of crime and disorder and the preservation of peace. 2. The protection of life, property, and personal liberty.

Subdivisions within fingerprint patterns

1. Ulnar, radial, and double loops 2. Plain, central pocket, and accidental whorls 3. Plain and tented arches

When considering each item observed in the scene, the investigator should ask 3 questions:

1. What is it and what function and what function did it serve? 2. What relationship does it have to any other items of evidence or to the scene itself? 3. What does it tell us about time and sequencing aspects?

On scene examination of human skin (alive):

1. adding machine paper technique

On scene examination of human skin (dead):

1. adding machine paper technique 2. cyanoacrylate fuming 3. magnetic powder 4. iodine fuming

3 basic scene integrity concerns:

1. addition of material to the scene. 2. Destruction of material in the scene 3. Movement of material in the scene

On scene examination of all non porous smooth surfaces:

1. cyanoacrylate fuming 2. powders (consider fluorescent for contrast) 3. Small particle reagent

Fire requires what to exsist?

1. heat 2. fuel 3. oxygen 4. uninhibited chemical chain reaction between the three *Known as the fire tetrahedron

The disipline of bloodstain pattern analysis considers...

1. location 2. shape 3. size 4. distribution 5. other physical characteristics of bloodstains

Primary methods for enhancing latent or slightly visible bloodstains

1. luminol 2. fluorescein 3. amido-black 4. leuco-crystal violet (LCV)

On scene examination of visible bloody prints:

1. photograph and lift or enhance with powder 2. Amido-black 3. Leuco-crystal violet

Scene conditions at fire scenes...

1. the fire damage itself 2. the resulting creation of unstable structures, 3. the presence of significant debris covering evidence 4. the fact that burned surfaces are black and do not reflect light effectively

Phenolphthalein consists of what three basic solutions

1. the phenolphthalein solution itself 2. ethanol 3. hydrogen peroxide as an oxidizer

Reference Scene Integrity: 3 techniques for handling supervisors or politicians are:

1. to enforce the use of standard personal protective measures 2. to enforce the use of scene entry log 3. to consider creating walking routes or observations points for authorized visitors

Stock solution of crystal violet:

1.5 grams of crystal violet powder in 100 ml of ethyl alcohol.

Ridge identification is based on at least 15 different ridge characteristics

1.ridge endings 2.bifurcations 3.short ridges 4.enclosures 5.ridge dot 6.ridge break 7.angular formations (deltas) 8.overlap 9.spurs 10.bridges 11.trifurcations 12.crossings 13.change overs 14.ridge pinch 15.loops

Long elliptical bloodstains indicate an impact angle of

10-30 degrees

When luminol is prepared from bulk the mixture is

100ml of distilled water, 0.1g of luminol, 0.7g of sodium perborate, and 0.5g of sodium carbonate

At what temperature does flash over occur?

1100 degrees F

Heat energy and thermal imaging wavelength?

12,000nm

Shortwave UV wavelength

180-254nm

Fill dirt is removed from gravesites in what size layers?

2 inch layers across the entire surface until a stratum or artifact is located.

Working solution of crystal violet

2ml of stock solution per 100 ml of water

Longwave UV wavelength

365-415nm

Crime scene search filters employ a broad passband filter encompassing _ nm?

390-520nm

Visible light spectrum in nanometers

400nm (violet)-700nm (red)

Near UV and Violet wavelength

415nm-485nm

Blue light wavelength

485nm-530nm

Orange-Red wavelength

570nm-700nm

Infrared wavelength

700nm-2000nm

Fingerprints consist of:

98% water and 2% a combination of grease, oils, salts, and amino acids

Identify sperm/seamen by testing for:

Acid phosphatase

Lifting of prints on rough non porous surface:

After powdering use a silicone based casting material, textured surface lifting tape, or textured surface lifting material

Evidence

Anything that tends to prove or disprove a fact in contention. p. 7

In situ

As found

Total station mapping

Automated surveying systems that use methods very similar to polar coordinates. A total station combines automated transits, lasers, and computer technology.

Barrier Filter

Barrier filter keeps the orginal wavelength from passing, but allows fluorescence energy to pass and be seen

At 455nm?

Biological fluids are easily observed in combination with an orange barrier filter

Name of latent processing technique that provided the idea to process fire scenes with a more critical eye...

Camphor technique.

Taxonomy of stains

Classification of stains

Most import tool the Crim Scene Technician uses in any crime scene?

Clean white light

Crime Scene Sketch

Could be anything from a freehand drawing to a computer generated to-scale document

Excitation Filter

Creates specific wavelength

Reflected light

Defines the color of the object we visulize. The object absorbs all colors except the one we visulize, ie blood absorbs all colors except for red.

DNA

Deoxyribonucleic acid Existence first reported in 1868 Structure discovered by Watson & Crick in the 50's

A clandestine gravesite may exhibit what appearances?

Disturbed soil, a grave mound, or even soil compaction. Vegetation around the immediate grave is likely to have been disturbed by the activity therefore it may be absent or in a state of regrowth that is dissimilar to the surrounding vegetation.

How do u test for copper in a defect?

Dithio oximide. 10% ammonia on the filter paper applied to the defect. Then spray with DTO. Positive test then it will turn green

On scene examination of wet rought non porous surfaces:

Dry, followed by powder and brush technique

Indented writings are most often recovered using what instrument

Electrostatic detection apparatus (ESDA)

ESLD

Electrostatic lifting devices

Fire patters do what?

Fire patterns show the progress of the fire, demonstrate the nature of the fuels involved and help to locate and isolate the actual origin of the fire. Visible and meaurable physical effects on the material in the scene.

"Fixing" the evidence

Fixing the evidence allows the investigator to functionally place the item back in the scene with some level of accuracy. p.171

3-4-5 rule

From a point three units from the grid corner on one axis, to a point four units from the same corner on the adjacent axis, the distance between the two points is five units.

Triangulation or rectangular coordinates on a grid

Grids are effective for large scale scenes where multiple teams are mapping with. I significant landmarks or in small scale scenes such as gravesites.A grid is created using stakes which become the landmarks.

Report-Search for latent fingerprints

Identify where fingerprinting was attempted, where it succeeded, and the nature of prints recovered (partial latent prints, palm prints, footprints)

Report-Collection of physical evidence

If the organization does not use an evidence log then a describtion of what was seized and where it was found.

Primary goal of forensics

Individualization, the examination of individual characteristics. p.25

Report-Conditions of the scene

Intended to identify the specific conditions that are pertinent to the investigation. i.e. cleanliness, level of disarray, describtions of items of evidence, odors etc.

Report-Characteristics of the scene

Intended to provide a general description of the scene and associated features of the seen such as doors, windows, openings, and geographical features in an outdoor scene. Furniture, appliances etc, present day to day are deceived in some detail as well.

Report-Factors pertinant to entry and exit

Intsded to deal with both known and possible avenues of approach and departure from the scene.

Report-Scene documentation

Is intended to describe the basic efforts taken to photograph and sketch the scene.

Reference basic scene integrity concerns: Golden Rule is?

Know who did what. P.17

At 485nm?

Latent prints developed in ninhydrin and be visualized using a yellow barrier filter

UVA

Longwavve UV

Fluorescence

Luminescence that happens as long as the object is exposed to an active energy source (ie ALS)

What types of nonintrusive technologies can be used to help locate a gravesite?

Magnetometers, ground penetrating radar, and infrared thermography; also a trained cadaver dog

Mitochondrial DNA analysis (mDNA)

Mitochondria are organelles in each cell where the production of Adenosine triphosphate (ATP) occurs. It is inherited only from the mother. It is gaining popularity in hair analysis.

SPR consists of...

Molybdenum disulfide suspended in water solution.

Basic Scene Integrity Concerns: Movement of Material

Movement is often the result of investigative processing techniques, but when such movement is unchecked and unrecognized it clouds the investigators understand of the crime scene. Movement of material significantly changes the relation aspects observed. i.e. moving the weapon from the hand of susp. P.16

Muzzle ranges: Close contact or hard contact

Muzzle is in direct contact with the skin or pressed into the skin

Triangulation on a baseline

On exterior scenes where evidence is not too widely scattered but where there are no adequate landmarks then a combination or baseline and triangulation can be applied. Reference points are marked on the baseline and evidence is triangulated using the reference points.

Report-additional examinations

Open to describing any additional evaluations or examinations.

ESLD works on what concept?

Opposites attract

What method drives every fire investigation?

Origin and cause

More about physical evidence power

Physical evidence has a greater power and ability than testimonial evidence in defining what happened at any crime. Physical evidence is what it is and it is tangible. p. 23

2nd developed technique for DNA testing

Polymerase Chain Reaction (PCR) Allowed the scientist to copy the DNA structure in small samples that would have been too small for RFLP technique. The statistical discrimination by PCR was significantly lower than RFLP.

5 basic objectives applied: Crime Prevention

Prevention includes actions and efforts designed to keep crime from occurring in the first place. i.e. community programs, youth programs, proactive patrol techniques, neighborhood watch. p.2

When using orange-red wavelengths us what barrier filter?

Red barrier filter

RUVIS

Reflected ultraviolet imaging system

Report-Environmental conditions

Reports on any weather or scene conditions noted at the time of the investigation.

Basic Scene Integrity Concerns: Addition of Material

Results in post incident artifacts. In effect the authorities end up creating evidence that was not there to begin with. Often used by defense to cast doubt or support alternating theory. p. 16

Basic Scene Integrity Concerns: Destruction of Material

Results in the loss of an item's evidentiary value. i.e. trampled dew trail, placing body in body bag causing loss of blood patters on clothing etc. p. 16

Method of evaluation of direction of force: 4R Rule

Ridge lines on Radial fractures are at Right angles to the Rear

450nm is good for?

Searching for/visualizing bite marks/bruises on human skin when used with a yellow barrier filter

3rd Major break through in DNA testing

Short tandem repeat (STR) Combined concepts of PCR but had statistical discrimination higher than RFLP. Ability to evaluate such small samples is significant but creates great risk for cross contamination.

UVB/C

Short wave UV

Define SPR

Small particle reagent

What can blood spatter analysis provide the investigator?

Specific information relating to where the associated event occured, what items were involved in the event, and the relative position of people and objects at the time of the event.

Physical Evidence

Takes the form of specific items found at the scene that are often collected for subsequent analysis and presentation. Sometimes it is not "collected" but documented through photograph/sketching. p.7

Crime Scene Mapping

The "process" of taking and documenting measurements of items present in the scene

What happens to blood stains when exposed to longwave UV?

The bloodstain absorbs all the light of that bandwidth, reflecting nothing back, thus will appear black

What four basic ways can light energy act on an object?

The energy will be reflected, absorbed, transmitted, or converted (or any combination of the four)

Evidence establishing photograph

The evidence establishing photograph are taken in such a fashion that the item is framed in conjunction with some other obvious landmark evident in the overall photograph.

Release of energy

The excited electrons fall back to normal energy state, releasing energy as light. This release is at a lower energy state than the original light.

Phosphorescense

The object continues to give off light in the converted wavelength even after removal of the energy source.

Overall photograph

The purpose of an overall photograph is to depict the general condition and layout of the scene. p.135

What happens to biological stains when exposed to longwave UV?

The will fluoresce with a lime green color even without a barrier filter

False positive reaction differences in luminol

There is a differenct in color, duration, and intensity. Flase positives usually is an immediate and intense reaction (almost a flash of light) that dies out quickly. Color is more light green/white. Toliets can present long duration blue violet color response

Evidence close-ups

They are close-up photos. The technician should try to fill the frame with the item of interest.

Report-Introduction

To identify who worked the scene examination, where the scene was, the time/date of examination, and a short explanation regarding the reason for examination.

Basic goals of incident management by a first responder can be achieved and expressed in 5 objectives:

To safely an effectively gain control of the scene the initial responding officer must: 1. Document the provided information 2. Not become a casualty 3. Provide for emergency care 4. Secure and control the scene and all those within it 5. Release the scene to the appropriate authorities (Dets or CSS) p.60

Define Truth:

Truth is defined by the collection of evidence, factual information that allows us to draw some conclusion about an event. The CSI realizes the significance of physical evidence in defining this truth. Unlike testimonial evidence, physical evidence does not lie. P.20

How is the presence of metallic lead in a suspected defect evaluated?

Using a sodium rhodizonate test

On scene examination of wet human skin:

Utilize the adding machine paper technique which is not negatively impacted by moisture.

455-485nm can be used to?

Visualize fluorescein reactions with latent blood. Typically using a yellow filter but an orange filter can be effective too when using the higher wavelengths

5 basic objectives applied: Crime Repression

When prevention fails, the police then seek to repress the criminal by actively investigating crimes and attempting to identify those responsible. Once identified the police are responsible for apprehending the criminals and bringing them to justice.

When should the reaction be halted in superglue fuming?

When the test print first begins to appear.

The color white represents...

a reflection of all wavelengths

The color black is...

an absorbtion of all wavelengths

Crime Scene Processing consists of:

an examination and evaluation of the scene for the purpose of recovering physical evidence and documenting the scene's condition in situ (as found). p. 1

Drip patterns occur when...

an object dripping blood is stationary for a period of time.

the presumptive tests are based on...

an oxidation-reduction reaction of chemicals that occurs in the presence of heme, a component of hemoglobin

Impact angle

approximate angle at which a droplet struck a surface

Unpredictable effects

are changes that occur in an unexpected or random fashion. i.e. found in the entry of police or EMS into a crime scene. often open doors/turned on lights then fail to report it. moving of evidence or haphazard opening of a revolver. p. 10

Dynamic patterns

are created by foreceful events, where fluid blood is projected out from a source under some force or compression. ie spatter, castoff patterns, arterial patterns, splashes, and spines

Patent Prints

are fingerprints caused by the deposit of contaminants such as bloody or greasy finger marks

Forensic firearms examiners

are the people who deal with internal ballistics. This includes the study and examination of the firearm itself, which includes ejection patterns, gunshot residue deposition, and other related aspects.

Fire patterns

are the predictable behaviors of fire that leave both blatant and subtle effects.

Bear claw shaped bloodstains indicate an impact angle of

between 40 and 60 degrees

circular bloodstains indicate an impact angle of

between 70 and 90 degrees

Rubberized casting compounds are not effected for recovering...

bite marks from human skin or for casting dirt impressions.

Saturation stains occur when...

blood is drawn into clothing, cloth, or pereable items. Often mar or destroy other blood patterns of interest

Contact stains occur when...

blood is transferred from one object to another through some form of contact ie. pattern transfers, wipes, swipes, and saturation stains

Directionality of a bloodstain is defined by

both the long axis of the stain and the presence of scallops, tails, and satellite spatter.

Responding officers objectives at a crime scene:

bring the site under control and coordinate resources. p. 59

Point of convergence

by visualizing a line aligned with the direction angle and extended back into the scene (reverse vectors) for a number of related spatters, a point of convergence will form where the lines cross each other on a surface

Damage patterns

can be evident on a single object or extended across an entire room. As an object is subjected to flame and heat from the fire, the exposed surfaces are damaged.

Luminol can have false positives from what items

certain metals, vegetable peroxidase, and cleaning cemicals

Predictable effects

changes to a scene that occur with some rhythm or regularity. i.e. Forensic entomology, rigor/livor mortis follows a somewhat predictable timeline. p.10

Investigators role in repressing crime:

conducting objective investigations in an effort to define who did what and why. P.18

Terminal ballistics

considered by the forensic pathologist, the effect of projectiles on the body

External ballistics

considers the trajectory of the bullet after leaving the weapon. The information derived is dependent upon the scene and the targets incolved.

"events" in event analysis

define gross aspects of the incident, such as approaching the scene, controlling the victims, killing the victims, etc

Luminol is a combination of

distilled water, luminol, sodium perborate, and sodium carbonate

Flurescein solution is

distilled water, sodium hydroxide, fluorescein, and zinc. 25ml of disilled water with 0.25g of fluorescein and 0.5g of zinc

Polar Coordinates

effective technique for mapping exterior scenes where the evidence is significantly scattered over an open area. Not suited to situations where line of sight is limited by woods/other obstacles. Based on a surveying technique. Using sighting device, measure two to three basic measurements from known point of the evidence.

Alternative light sources (ALSs) allow the crime scene technician to...

employ a variety of narrow wavelengths of the light spectrum in an effort to identify, visualize, and document a variety of different types of physical evidence.

Locard's Priciple of Exchange

every contact leaves a trace. p.25

Plastic Prints

fingerprint impressions where a print has been deposited in a soft surface such as wax p.27

Typical pattern transfers include...

hand or foodprints and patterns of bloodied knife blades or blunt force weapons

Rubberized casting compounds are most effective when used on...

hard substrates such as metals, wood, bone, or plastic.

Special condition surfaces:

human skin, adhesive tapes, and blood prints

At 525-530nm?

in combination with an orange barrier filter are excellent for developing and visualizing latent fingerprints with fluorescent powders

Latent Prints

invisible prints created by the deposit of normal body secretions.

Rectangular coordinate method

is best suited for crime scenes with clear and specific boundaries (e.g., interior walls). It is a fast and effective method. The technician fixes the evidence by measuring at right angles from the evidence to the surrounding walls and surfaces. Generally only two measurements from the center of mass to document each item. Thus less precise than other techniques and it does not "fix" the evidence since it can be rotated in that position.

Baseline Coordinates

is best suited for exterior scenes without evident landmarks. Begins with a datum point-a location from which the baseline will extend. It is set by triangulating it to a set of nearby landmarks. Once datum is set a baseline is extended across a cardinal direction (N, S, E, W) as far as necessary. Best to use actual tape measure but can use line or string, with ref points marked on the line. Then measure items at a right angles to the baseline then the distance along the baseline to the datum point.

Testimonial Evidence

is collected through the interview and interrogation of witnesses. Major flaw: it is offered by humans and humans are subjective creatures. p.7

Cross contamination

is directly associated with Locard's Principle of Exchange and caused by inappropriate handling of evidence. p. 25

Triangulation method

is effective for fixing evidence. Rules are based on whether an item has a regular or irregular shape. Items with a regular shape-will not change with movement, contain specific identifiable points-are fixed with a min of 4 straight-line measurements from two landmarks in room to two points on article. (i.e. furniture, guns, knives). Irregular shape items-items that will change shape when moved-documented with two measurements from the center mass to two distinct landmarks and a measurement of overall width of item. (i.e. blood pools, clothing, circular drink glass upright). Regular shaped items-2 "triangles" (4 measurements) Irregularly shaped objects- 1"triangle" (2 measurements)

Most basic consideration of light

is ensuring the presence of light of sifficient illumination on scene in order to conduct a thorough search.

Absolute chronology

is related to timing aspects.

The "incident" in event analysis

is the overall situation being investigated

Relative chronology

is the seuencing of event segments in relation to one another. Relative chronology is thetrue back bone of the reconstruction. No association with absolute time.

Area of origin

is the three dimensional space above the convergence point

Sodium rhodizonate test consists of what?

it requires 3 working solutions. 10-15% solution of glacial acetic acid. then a working solution of sodium rhodizonate (4g to 100ml of water), which should turn scarlet if lead is present. then 5% hydrochloric acid which should turn the scarlet to blue violet

Transmission of light relates to

its penetrating power;light energy can pass through and object

Conversion of light

light energy can be converted from one wavelength to another, creating the condition known as luminescence.

Thermal imaging has been used effectively to...

locate decomposing bodies and to find hot spots in fire scenes. Also available in a handheld device to distinguish between recent and older tire marks on accident scenes.

Relational Details

maifest themselves through the investigators ability to physically place items in the scene. i.e. void in spatter, clustering of shell casings able to establish a correlation between various objects. p. 11

Functional Details

manifests themselves in the operating condition of items in the scene. i.e. is the weapon capable of operating normally? p.11

"event segments" in event analysis

microcomponents of the event. sevent segments are snapshots of specific moments in time, detailing specific actions that occurred. Event segments are always defined by specific data.

Muzzle ranges: Intermediate range

muzzle is between 5-40 inches. intermediate range gunshot wounds are deduced from the presence of stippling around the wound. Different types of powders travel and embed at different distances, resulting in an ability to define the wound as intermediate

Muzzle ranges: Loose contact

muzzle is in extremely close proximity to the skin but at the moment of firing a gap is created between the two

Muzzle ranges: Near contact

muzzle is not more than 5 inches from the skin

Critical consideration in superglue fuming is...

not to overfume the latent print.

Fly spot

occur as the result of fly activity in a scene. The movement of flies can track blood from a body or blood source and deposit it on surrounding walls and surfaces. Flies also regurgitatae blood onto these surfaces.

Swipe pattern

occur when a bloody object makes contact through some for of lateral motion with an unstain object

Wipe patterns

occur when a prexisting stain is disturbed by another object

Void patterns

occur when a secondary object is present between a bloodstain event and a nearby surface. Voids appear most often in spatter events

Splash patterns

occur when a volume of blood is projected into the scene with minimal force

Cast off patterns

occur when an object is bloodied and then moved or swung with some force.

Transitory effects

oftentimes they are fleeting. Ultimately, time and environment will destroy any transitory effects. i.e. heat of a burning cigarette, presence of ice in a glass, odors of chemicals or colognes. p.11

Porous surface examples:

paper, cardboard, untreated wood

Soil Sample Collection

place in a small, clean, pint-sized, paint cain. Generally 1/2 to 1 cup of material is suggested for any analysis.

Crime scene entry control log is intended to:

provide a running record of everyone who entered the scene, when they entered, why they entered, and what time they left. p.98

Infrared wavelengths are most often employed in...

questioned document examinations. Has little direct application to crime scene processing.

Passive Stains

result from an action other than a directed force to a blood mass ie. contact patterns, blood clots, drip patterns, drip trails, and blood pools or flows

Arterial patterns

result from blood in volume that is projected into a scene under pressure from an artery or heart

Smoke and soot patterns

result from the outflow of fire products

First break through in DNA testing

technique known as Restrictive Fragment Length Polymorphism (FELP) discovered in 1984 by Alec Jefferys relied on large and undegraded samples

Identify the presence of saliva by:

testing for the presence of amylase or starches.

Directionality of the stain

the direction the droplets were traveling at the moment they struck a surface

Stippling or tattooing is

the embedding of unburned and partially burned gun powder residues in the skin

SPR reacts with what in a latent print?

the fats found in the latent print

Interpretive value of evidence

the full meaning of evidence is a function of time and the items surroundings (Rynerson & Chisum) In other words its an issue of context than mere content. P.8

All radiant energy is measured by...

the length of its wave (from peak to peak), wavelengths are measured in nanometers

Refractive Index (RI)

the manner in which it allows light to pass through it

Consdieration is also given to...

the nature of the object and how one would typically touch or manipulate the item.

The basis of all crime scene reconstruction is...

the scientific method

Intrusive techniques for locating a grave are...

the use of probes and vapor monitors. Vapor monitors are used to detect decomposition gases

Muzzle ranges: Indeterminate range:

this determination means that no conclusion can be drawn on muzzle distance. This determination is found in situations where there are no markings except for the bullet defect

How is fluorescein reaction seen

using an ALS set between 455-485nm with a yellow barrier filter. orange will also work

Char patterns

usually result from direct flame involvement

Nonporous smooth surfaces:

varnished and painted surfaces, plastic surfaces, glass

Orange and red wavelengths are effective for...

viewing inks on items present in the scene as well as questioned documents. May also assist in visualizing subcutaneous bruising.

Nonporous rough surfaces:

vinyl, leather, textured countertops, and other textured surfaces

Pyrolysis

when heat breaks down the fuel source into gas and vapors that burn

Expiratory spatter

where there is blood present in the airway and exhalation of the victim will break the blood into small droplets, which are forced out of the airway