A look into evidence gathering and processing The Crime Scene A look into evidence gathering and processing

Crime Scene Definition Crime Scene vs. Scene of the Crime Includes planning areas, flight paths, staging areas, surveillance Location of the actual crime

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”

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

What is the Job Title? In Albany, 8 detectives make up a “support unit” that collects all areas of evidence instead of individual units

Evidence 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.

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.

Value 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 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 continued 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 Evidence Class evidence - evidence that can only be grouped into a general category; cannot be pinpointed to a direct person or object ex. Black Lab Hair Individualized evidence - evidence that can be pinpointed to only one individual or object; unique ex. Fido’s hair (a black Labrador) through DNA

Class versus Individualized continued Trace Evidence Hair Class Dog Hair Black Labrador Retriever Hair DNA from hair individualized to Fido (a black Labrador Retriever) Individualized

“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

Processing 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

Processing 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

Priorities of a Crime Scene Save and preserve life Provide first aide Arrest, detain, remove any suspect Make sure scene is safe for entry by investigators and forensic examiners Secure and preserve crime scene, keeping record of all who enter/exit

Priorities of a Crime Scene Record and preserve evidence that is perishable 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 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

Secure 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

Record the Scene Limited time available to work a crime scene Three methods of crime-scene recording: Photography Sketches Notes

Lockard’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.

Forensic 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

Forensic 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

Forensic 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)

Forensic 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

Sketches 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

Sketches Often use number or letter cards by evidence Finished sketch is finished back at the lab using computers and drafting materials

Notes 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 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 search 2) Grid method 3) Strip or line method 4) Quadrant or zone search

Systematic Search for Evidence Spiral Grid Line/Strip Quadrant/ Zone

Systematic 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

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

Evidence Collection Kit

Sample 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

Maintaining 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