The Crime SceneThe Crime Scene

A look into evidence gathering and processing

A look into evidence gathering and processing

Crime Scene DefinitionCrime Scene Definition

Crime Scene vs. Scene of the CrimeCrime Scene vs. Scene of the Crime

Includes planning areas, flight paths, staging areas, surveillance

Location of the actual crime

What is the Job Title?What is the Job Title?

• In the United States, crime scene investigators are usually called “criminalists”

• In the United Kingdom, crime scene investigators are usually called

“scene of crime officers”

• In the United States, crime scene investigators are usually called “criminalists”

• In the United Kingdom, crime scene investigators are usually called

“scene of crime officers”

What is the Job Title?What is the Job Title?

• Job titles in forensic fields vary widely from jurisdiction to jurisdiction

• Example: A crime scene analyst is a civilian employed by the police department in Las Vegas- allowed to carry guns- depending on the department, analysts can be civilian or law enforcement

• Job titles in forensic fields vary widely from jurisdiction to jurisdiction

• Example: A crime scene analyst is a civilian employed by the police department in Las Vegas- allowed to carry guns- depending on the department, analysts can be civilian or law enforcement

What is the Job Title?What is the Job Title?

• In Albany, 8 detectives make up a “support unit” that collects all areas of evidence instead of individual units

• In Albany, 8 detectives make up a “support unit” that collects all areas of evidence instead of individual units

Evidence TypesEvidence Types

1. Physical or Real evidence: A tangible object related to a crime.

2. Testimonial evidence: Verbal accounting of an incident by a witness, victim or suspect.

1. Physical or Real evidence: A tangible object related to a crime.

2. Testimonial evidence: Verbal accounting of an incident by a witness, victim or suspect.

Evidence Types cont.Evidence Types cont.

3. Direct evidence: That which, if true, proves a fact in dispute.

4. Indirect or circumstantial: That which if true tends to establish an issue in dispute by proving another associated fact which supports the original evidence.

3. Direct evidence: That which, if true, proves a fact in dispute.

4. Indirect or circumstantial: That which if true tends to establish an issue in dispute by proving another associated fact which supports the original evidence.

Value of EvidenceValue of Evidence

• Physical evidence: Can’t lie, die, quit forget ….etc.

• Testimonial evidence: may change, be unreliable, mistaken or source can become unavailable during the case.

• Physical evidence: Can’t lie, die, quit forget ….etc.

• Testimonial evidence: may change, be unreliable, mistaken or source can become unavailable during the case.

Physical Evidence IssuesPhysical Evidence Issues

• Not recognized, identified or overlooked• Not legally collected• Not properly collected• Not properly packaged• Not properly stored• Not properly tested• Chain of custody issues

• Not recognized, identified or overlooked• Not legally collected• Not properly collected• Not properly packaged• Not properly stored• Not properly tested• Chain of custody issues

Evidence Issues continuedEvidence Issues continued• Most of the mistakes made in the

collection, securing and testing of evidence can be attributed to the lack of training and understanding.

• Most of the mistakes made in the collection, securing and testing of evidence can be attributed to the lack of training and understanding.

Ex. OJ Simpson Case

- mishandled evidence

Class versus Individualized EvidenceClass versus Individualized Evidence• Class evidence - evidence that can only

be grouped into a general category; cannot be pinpointed to a direct person or objectex. Black Lab Hair

• Individualized evidence - evidence that can be pinpointed to only one individual or object; uniqueex. Fido’s hair (a black Labrador) through DNA

• Class evidence - evidence that can only be grouped into a general category; cannot be pinpointed to a direct person or objectex. Black Lab Hair

• Individualized evidence - evidence that can be pinpointed to only one individual or object; uniqueex. Fido’s hair (a black Labrador) through DNA

Class versus Individualized continuedClass versus Individualized continued

Trace Evidence

Hair

Dog Hair

Black Labrador Retriever Hair

DNA from hair individualized to Fido (a black Labrador

Retriever)

Class

Individualized

“Common Source” Not “Match”“Common Source” Not “Match”• When two objects share a class identity• For example, white tennis shoes

– Common source can be the factory, owner, or even where found

– Suspect who owns white tennis shoes and one is left at crime scene, try to see if the CS shoe came from a common source as the one in his apartment

• Example, fibers on a body in ditch– Fibers on body belong to an automobile– Find a suspect, and try to see if fibers in his

car are from common source as the fibers on the body

• When two objects share a class identity• For example, white tennis shoes

– Common source can be the factory, owner, or even where found

– Suspect who owns white tennis shoes and one is left at crime scene, try to see if the CS shoe came from a common source as the one in his apartment

• Example, fibers on a body in ditch– Fibers on body belong to an automobile– Find a suspect, and try to see if fibers in his

car are from common source as the fibers on the body

Processing the Crime SceneProcessing the Crime Scene• Crime labs need evidence to function

- Anything which is legally submitted to a court as a means of ascertaining the truth of an alleged matter of fact under investigation before it.- includes evidence that provides a link between the victim and the assailant

• Specifically, they need physical evidence

• Crime labs need evidence to function- Anything which is legally submitted to a court as a means of ascertaining the truth of an alleged matter of fact under investigation before it.- includes evidence that provides a link between the victim and the assailant

• Specifically, they need physical evidence

Processing the Crime SceneProcessing the Crime Scene• Important to remember that crime

labs DO NOT solve crime• Only investigations by police solve

crimes• Forensics merely helps the police

to do their job

• Important to remember that crime labs DO NOT solve crime

• Only investigations by police solve crimes

• Forensics merely helps the police to do their job

Priorities of a Crime ScenePriorities of a Crime Scene

1. Save and preserve life2. Provide first aide3. Arrest, detain, remove any suspect4. Make sure scene is safe for entry by

investigators and forensic examiners5. Secure and preserve crime scene,

keeping record of all who enter/exit

1. Save and preserve life2. Provide first aide3. Arrest, detain, remove any suspect4. Make sure scene is safe for entry by

investigators and forensic examiners5. Secure and preserve crime scene,

keeping record of all who enter/exit

Priorities of a Crime ScenePriorities of a Crime Scene

6. Record and preserve evidence that is perishable

7. Identify and locate any witnesses; keep separate if possible

(Don’t want stories to be contaminated)8. Communicate with senior officer who will

coordinate initial investigation

6. Record and preserve evidence that is perishable

7. Identify and locate any witnesses; keep separate if possible

(Don’t want stories to be contaminated)8. Communicate with senior officer who will

coordinate initial investigation

Secure and Isolate the Crime SceneSecure and Isolate the Crime Scene• The first officer on the scene must

follow the previously listed priorities• First priority is to administer first aide

and arrest the perpetrator• Must also take efforts to remove

unauthorized persons from the scene• Crime scene is marked off, often larger

than is and an enter/exit area created

• The first officer on the scene must follow the previously listed priorities

• First priority is to administer first aide and arrest the perpetrator

• Must also take efforts to remove unauthorized persons from the scene

• Crime scene is marked off, often larger than is and an enter/exit area created

Secure and Isolate the Crime SceneSecure and Isolate the Crime Scene• All who enter must be logged in/out;

controls evidence tampering• Protective clothing is put on to avoid

cross-contamination• The enter/exit area of the perpetrator is

recorded as well• Police must ensure suspect can not

return to the scene to destroy evidence

• All who enter must be logged in/out; controls evidence tampering

• Protective clothing is put on to avoid cross-contamination

• The enter/exit area of the perpetrator is recorded as well

• Police must ensure suspect can not return to the scene to destroy evidence

Record the SceneRecord the Scene

• Limited time available to work a crime scene

• Three methods of crime-scene recording:

1. Photography2. Sketches3. Notes

• Limited time available to work a crime scene

• Three methods of crime-scene recording:

1. Photography2. Sketches3. Notes

Lockard’s Theory: ReviewLockard’s Theory: Review

• Dr. Edmund Locard’s theory for the exchange of evidence is widely recognized as the cornerstone of forensic science.

• Locard’s theory: Whenever two objects come into contact, a transfer of material will occur. Evidence that is transferred can be used to associate objects, individuals or locations.

• Dr. Edmund Locard’s theory for the exchange of evidence is widely recognized as the cornerstone of forensic science.

• Locard’s theory: Whenever two objects come into contact, a transfer of material will occur. Evidence that is transferred can be used to associate objects, individuals or locations.

Forensic PhotographersForensic Photographers

• Important: Scene must be unaltered- if changed, photos could be inadmissible as evidence

• Photos are taken of entire crime scene, including surrounding areas; enter and exit areas taken at various angles; adjacent rooms

• Bodies are also heavily photographed in relation to where they are in the scene

• Important: Scene must be unaltered- if changed, photos could be inadmissible as evidence

• Photos are taken of entire crime scene, including surrounding areas; enter and exit areas taken at various angles; adjacent rooms

• Bodies are also heavily photographed in relation to where they are in the scene

Forensic PhotographersForensic Photographers

• As physical evidence surfaces, they are photographed; often with something next to them to indicate size (ruler or measuring tape)

• Photographers are only able to begin taking photos once they have been given the okay from the crime scene manager

• As physical evidence surfaces, they are photographed; often with something next to them to indicate size (ruler or measuring tape)

• Photographers are only able to begin taking photos once they have been given the okay from the crime scene manager

Forensic PhotographerForensic Photographer

• Equipment:– 35mm and digital (not evidence)

cameras; corresponding film– Standard light (flash)– Colored filters, light beams, UV

(stains/fingerprints after treated with superglue or DFO), violet (gunshot residue/blood), blue and green light (prints/fibers/urine/semen)

• Equipment:– 35mm and digital (not evidence)

cameras; corresponding film– Standard light (flash)– Colored filters, light beams, UV

(stains/fingerprints after treated with superglue or DFO), violet (gunshot residue/blood), blue and green light (prints/fibers/urine/semen)

Forensic PhotographerForensic Photographer

• Key point about photography is that it allows the police to reopen a crime scene quickly, like a busy street- all evidence has been captured on film

• Ready 24/7• Extremely difficult job because reliant

on this person’s experience to get all data

• Key point about photography is that it allows the police to reopen a crime scene quickly, like a busy street- all evidence has been captured on film

• Ready 24/7• Extremely difficult job because reliant

on this person’s experience to get all data

SketchesSketches

• After the photographer is finished, crime scene investigators make a rough sketch of scene

• Shows the location of all objects• Objects are located from two fixed

points in the room like walls or a doorknob; called DATUM

• All measurements are made with a tape measure

• After the photographer is finished, crime scene investigators make a rough sketch of scene

• Shows the location of all objects• Objects are located from two fixed

points in the room like walls or a doorknob; called DATUM

• All measurements are made with a tape measure

SketchesSketches

• Often use number or letter cards by evidence

• Finished sketch is finished back at the lab using computers and drafting materials

• Often use number or letter cards by evidence

• Finished sketch is finished back at the lab using computers and drafting materials

NotesNotes

• Notes are continuously gathered at a crime scene

• Must identify the time evidence was found, location, description, who and how item was packaged

• Notes can also be taken using a tape recorder and by video; later must all be written down

• Notes are continuously gathered at a crime scene

• Must identify the time evidence was found, location, description, who and how item was packaged

• Notes can also be taken using a tape recorder and by video; later must all be written down

Systematic Search for EvidenceSystematic Search for Evidence• A thorough, systematic search of the

crime scene necessary for court• Not necessarily done by forensic

scientists• There are four general search patterns

1) Spiral search2) Grid method3) Strip or line method4) Quadrant or zone search

• A thorough, systematic search of the crime scene necessary for court

• Not necessarily done by forensic scientists

• There are four general search patterns1) Spiral search2) Grid method3) Strip or line method4) Quadrant or zone search

Systematic Search for EvidenceSystematic Search for Evidence

Spiral

Quadrant/

Zone

Line/Strip

Grid

Systematic Search for EvidenceSystematic Search for Evidence• A hand-held vacuum with a special filter

can be used to collect evidence• Crime scene evidence is extended into

the autopsy room:– victim’s clothing; fingernail scrapings; head

and pubic hairs; blood; vaginal, anal and oral swabs; recovered bullets from the body; hand swabs from shooting victims

• A hand-held vacuum with a special filter can be used to collect evidence

• Crime scene evidence is extended into the autopsy room:– victim’s clothing; fingernail scrapings; head

and pubic hairs; blood; vaginal, anal and oral swabs; recovered bullets from the body; hand swabs from shooting victims

Collect and Package Physical EvidenceCollect and Package Physical Evidence• Each different item or similar items

collected at different locations must be placed in separate containers

• Pill bottles, manila envelopes, and paper bags are common evidence containers; sealed with tape

• Forceps are used to pick up small items• Evidence is then sent to lab for

examination

• Each different item or similar items collected at different locations must be placed in separate containers

• Pill bottles, manila envelopes, and paper bags are common evidence containers; sealed with tape

• Forceps are used to pick up small items• Evidence is then sent to lab for

examinationNote: Bloody objects DO NOT go in plastic bags; mold grows!

Evidence Collection KitEvidence Collection Kit

Sample PackagingSample Packaging• Information needed on evidence collected

– Date and time of collection– Case identification number– Who collected it– Description of item or items collected– Where found

• Chain of custody - document that shows record of the evidence’s movement from the time of collection until it is presented in court

• Information needed on evidence collected– Date and time of collection– Case identification number– Who collected it– Description of item or items collected– Where found

• Chain of custody - document that shows record of the evidence’s movement from the time of collection until it is presented in court

Maintaining a Chain of CustodyMaintaining a Chain of Custody• As evidence is collected, the

evidence bag is initialed by the collector and dated

• Anyone who possess the evidence during the investigation must sign for it as a record

• Failure to document can have evidence excluded from case/trial

• As evidence is collected, the evidence bag is initialed by the collector and dated

• Anyone who possess the evidence during the investigation must sign for it as a record

• Failure to document can have evidence excluded from case/trial