Crime Scene Documentation Study Set

What is forensic science?

Forensic science is the application of science to criminal and civil laws that are enforced by police agencies in a criminal justice system.

What is the largest forensic organization in the world?

the american academy of forensic science

What is the defintion of evidence?

anything that tends to prove or disprove a fact in contention

what are the three main types of evidence?

• physical

• documentary

• testimonial

Physical evidence

tangible items you can collect, analyze, and show a jury

Documentary evidence

written reports and photographs

Testimonial evidence

verbal oath-bearing statements

What is chain of custody?

a list of all people who came into possession of an item of evidence

Locard’s Exchange Principle

whenever two objects come into contact with one another, there is exchange of materials between them

Daubert Criteria

1. whether the scientific technique or theory can be and has been tested

2. whether the technique or theory has been subject to peer review and publication

3. the technique’s potential rate of error

4. existence and maintenance of standards controlling the technique’s operation

5. whether the scientific theory or method has attracted widespread acceptance within a relevant scientific community

What are some of the duties of a first responder at a crime scene?

• ensure the safety of self and others

• isolate and remove witnesses

• detain or arrest any suspects

• make notes

• protect evidence

• establish “path” through scene

• establish a command center

• maintain crime scene log

• control who enters scene

• note time and to whom scene is released

what are some biohazards at a crime scene

exposure to infectious blood, body fluids

what are chemical hazards at a crime scene

clan labs, toxic gases, combustible materials

what are sharps at a crime scene

hypodermic needles, broken glass, other sharp objects

what is the order of operations of processing a crime scene

1. contact someone already on scene

2. conduct an initial walk through of the scene

3. search the scene for fragile evidence and collect

4. document the scene via photography

5. conduct a search of the scene

6. place evidence markers in scene

7. document the scene via photography again

8. sketch/diagram the scene

9. collect open view evidence

10. conduct another more thorough search

11. collect all evidence

12. conduct final walk through

what is fragile evidence?

any evidence that would lose its evidentiary value if not promptly and properly preserved and collected

what does in situ mean

in the original place

who are the team members of a crime scene unit

• team leader

• photographer

• measurement collector and sketch preparer

• evidence recorder and collector

• specialists

what are some of the duties of a team leader at a crime scene?

• assume and maintain control

• conduct initial walk through

• procure additional equipment if necessary

• determine search patterns

• assign duties to team members

• designate command post

• exchange information between search and investigative personnel

• coordinate with other LE and Specialists

• conduct final walk through

• release the scene upon completion

• document (in detail) the above actions in narrative

What are some of the duties of the photographer?

• Photograph entire scene before entry
• Photograph victims, crowd, and vehicles
• Photograph overall, medium, close-up, with scale
• Coordinate with other team members to ensure photography of evidence before moving
• Photograph impression evidence
• Prepare photographic log
• Secure and submit digital photographs to evidence vaults
• Document (in detail) the above actions in narrative

What are some of the duties of the measurement collector and sketch preparer?

• Create a rough sketch of the entire scene
• Determine best measurement technique for scene/evidence
• Obtain assistance for collecting measurements, double check
• Collect measurements of scene
• Complete measurement log
• Create finished sketch and formal measurement log
• Ensure necessary administrative information is on sketch
• Document (in detail) the above actions in narrative

What are some of the duties of the evidence collector and recorder?

• Ensure evidence is photographed initially
• Place evidence photographic markers
• Ensure evidence is photographed again with markers and scales
• Collect evidence (be conscious of cross-contamination)
• Seal, sign and date evidence packaging
• Transport and secure evidence
• Note any evidence transfers
• Create evidence log
• Document (in detail) the above actions in narrative

What are some things to consider before contacting a specialist to your crime scene?

• Competence and reliability of the specialist
• Ability of specialist to work a scene within LE guidelines
• Role of the specialist in presenting expert testimony

What are some examples of specialists that you can call out to your crime scene?

Anthropologist
Bloodstain Pattern Analyst
Bomb Technician
Engineer
Entomologist
Medical Examiner
Search and Rescue teams
Dive Teams
Surveyor
Criminalist

What are the six most common used search patterns?

Line and Strip
Grid
Spiral
Ray
Zone
Link

When is it good to use a line search?

• best when search boundaries are well established

• good for uneven terrain

when is it best to use a strip search?

best when search boundaries are well established

when is it best to use a grid search?

• when you want a very thorough search

• best when search boundaries are well established

spiral search

Good for only
one person
Light evidence
to heavy
evidence

Hard to keep a
“circle” so
evidence may
be missed

wheel/ray search

Searchers move
from outside
boundaries toward
center
Not preferred

zone search

AKA Quadrant
search
Team members
assigned to search
each section

What are the different types of sketches?

• Bird’s Eye View

• Cross Projection

• Elevation Sketch

• Three Dimensional

What tools can you use to measure at a crime scene?

• Laser Distance Measurer

• Tape Measurees

• Total Station System

• 3-D Scanner

center mass

• two measurements

• when exact placement is not necessary

• when exact size is not necessary

• object can be rotated 360 degrees

multiple measurements

• at least 4 measurements

• when exact placement is necessary

• cannot rotate object in diagram

• good for linear objects

• body

Measurement techniques

Rectangular Coordinates/Rectangulation
Triangulation
Baseline Coordinates
Polar Coordinates
Total-Station Systems/3-D Scanning

what are the steps to processing a vehicle?

• documentation in situ

• search for evidence

• mark evidence

• document again

• collect evidence

what are some photograph identifiers for a vehicle?

• vehicle license plate

• VIN

• vehicle info sticker

• bumper stickers

• parking pass

• inspection stickers

• decals

class characteristics

properties of
evidence that can be associated
only with a group and never with a
single source
• Example: left size 10 Nike shock

individual characteristics

properties that can be attributed to
a common source with a high
degree of certainty
• Example: random wear pattern
on shoe

what should be on each evidence package?

• case number

• date and time

• item number

• name of collector

• initials/date on seal

• description of contents

what are the three methods of collecting trace evidence?

• visual

• trace tape

• vacuuming

crime scene photography is done in ______ mode

manual

aperture is meausured in _______.

f-stops

the smaller the f-stop the ____ the opening

larger

what kinds of photos are taken at a crime scene?

• overview

• medium range

• close-up

• close-up with scale