Processing a Crime Scene UNIT OVERVIEW Processing a Crime Scene Evidence Team Crime Scene Searches Evidence Collection and Packaging Chain of Custody Legal Precedent Physical Evidence

Locard’s Exchange Principle Every contact leaves a trace! Whenever two objects come together they must affect each other in some way. Something is likely to be exchanged between them! Physical Evidence - encompasses any object that can establish a crime has been committed or can provide a link between a crime and its victim or perpetrator

A group of professionals trained in a variety of special disciplines Crime Scene Team A group of professionals trained in a variety of special disciplines First police officer on the scene (Team Leader) Medics (if necessary) Photographer and Note taker Sketch team Evidence Recovery Personnel Lab experts/specialists

Team Leader (1st Officer) Secure and Isolate the Crime Scene Obtain medical attention Preserve and protect evidence Exclude unauthorized personnel (Every individual who enters is potential destroyer of evidence) Designate officer in charge Establish boundaries Evaluate area

1) Team Leader Assume control and assess scene Determine search pattern and assignments Coordinate with groups involved Continuously evaluate work Release Crime Scene

Crime Scene Survey Walk-through Purpose: Mentally prepare a reconstruction theory Note any conditional evidence that could change over time Note environmental and weather conditions Note points of entry or exit, as well as paths of travel within the crime scene Record initial observations of who, what, where, when, and how Identify special needs within the crime scene for personnel, precautions, or equipment and notify superior officers or other agencies

Recording/ Documenting the Scene Need to permanently record the crime scene so original state is not lost Documentation is required for presentation at trial Photography Sketches Notes

2)Note taker Must include written description of the scene with enough detail to refresh memory months or years later date, time, description of the location weather and environmental conditions description of the crime location of the evidence relative to other key points the names of all people involved modifications that have occurred and other relevant information

3) Photographer Videography Secondary to still photos allows for narration (non-subjective) and different perspectives Photos of entire scene and surroundings (overlap by 30%) mid-range to close-up photos with various angles of each piece of evidence Photograph evidence before it’s moved (including fingerprints, casts, etc.) Photograph evidence both in wide view (position at scene) and close-up (with scale) All photos logged

Capture Crime Scene

Wide angle lenses are used to distort the truth or emphasis it

Details preserved

Proper Technique (Courtesy of Phil Orlando)

38 Caliber and 44 Caliber

4) Sketch Artest (Rough and Finished) Includes date, time, scale Gives reference points and distance measurements Names of investigators, victims, suspects A legend (key) Finished Sketch Can be hand drawn or computer generated Drawn to scale Aesthetic appearance

5) Evidence Recovery Personnel Package evidence separately Maintain chain of custody and evidence log Ensure proper safety of collection (e.g., infectious materials) What to think about? Who did it? What happened? When did it happen? How did it happen? Did it happen here or was another crime scene involved? Who is the victim? Why was this crime committed? What evidence is there to help prove the motive and the crime? 

Crime Scene Searches Must be thorough and systematic Search for evidence must be conducted immediately How investigation is carried out depends on locale, size of area, actions of suspects & victim(s) at scene Steps: One person supervises or coordinates collection of evidence Scene subdivided into segments Areas searched must include all possible points of entry and exit

Methods of Searching a Crime Scene Line or strip method Best in large, outdoor scenes Need many people to be most effective Move in one direction at a time Must move slow and cover the area multiple times

Grid Search A double-line search Effective, but time-consuming Can be done with fewer people in an large, open area (fields or woods)

Zone or quadrant method Most effective in houses, buildings, or large areas Teams are assigned zones for searching Usually based on floor plans or land areas

Spiral method Best on small, circular crime scenes May move inward or outward (being careful not to disturb evidence Best used where there are no/limited physical barriers

Physical Evidence Includes Anything from massive objects to microscopic traces Evidence may be obvious, but some can only be detected through examination in the crime lab Examples: Victims clothing (Fibers) Fingernail scrapings Head and pubic hairs Blood (for typing and DNA typing purposes) Recovered bullets Hand swabs from shooting victims (for gunshot residue analysis) Soil

Collecting & Packaging Evidence The most fragile evidence is collected and packaged first Different types of evidence require specific or special collection and packaging techniques The type of container depends on the sample Changes can occur through: Contamination Breakage Evaporation Accidental scratching or bending Improper or careless packaging

Types of Packaging Many items are packaged in a primary container and then a secondary one. Pill bottles, vials, manila envelopes, and plastic bags are good for most evidence. Trace evidence may be placed on a piece of paper which is then folded in a particular way called a “druggist’s fold.” Secondary containers such as paper bags, plastic bags, canisters, packets, or envelopes are used depending on the type and size of the evidence.

Maintaining the integrity of evidence Item should be kept in original condition if possible Submit to the lab intact Blood, hairs, fibers, soil particles - should not be removed from garments, weapons or other items that bear them (send entire object for testing) Bloodstains and scraping should be transferred to a moistened swab or cut out area of object bearing stain Biological evidence such as dried blood should be packaged in paper ~ Liquid blood can be collected in a glass tube but SHOULD NOT be frozen Packages should be sealed and marked with your initials, date collected, and vital information

ALL handlers are responsible for the integrity the evidence Chain of Custody - a written record of all those who have had possession of an item of evidence, beginning at the time of collection (The first person who comes in contact with that evidence should fill out a chain of custody tag.) The evidence container must be marked for identification. The collector’s name or initials are placed on the seal. If evidence is turned over to another person, the transfer must be recorded.

Submission to Laboratory Evidence forms must accompany all evidence Brief history of case is included Type of examinations requested List of items submitted for examination Obtain Standards/Reference Samples and Controls Examination of evidence requires a comparison with a control for verification Quality & quantity of reference samples lends weight to their value

Safety Guidelines from the International Association for Identification Safety Committee Personnel wear a minimum of latex gloves (double gloved) and protective shoe covers. Use of masks/respirators, goggles or face shields Be alert to sharp objects (knives, hypodermic needles, razor blades…) Maintain a red biohazard plastic bag for disposal of potential infectious materials Note taking done with non-contaminated gloves Soiled/torn protective equipment should be removed immediately and disinfected No eating or drinking at the crime scene Personal clothing that may have been contaminated should never be taken home

Legal Considerations at the Crime Scene “Unreasonable search and seizure” removal of evidence must conform to 4th amendment: “The right of the people to be secure in their persons, houses, papers and effects against unreasonable searches and seizure, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched and the persons or things to be seized.”

Allowances for Warrantless searches Existence of an emergency (exigent circumstances) The need to prevent the immediate destruction of evidence. In plain view A search of a person or property within the immediate control of the person provided it is made incident to a lawful arrest. Consent of the person involved.

MINCEY v. ARIZONA (U.S. Supreme Court, 1978) Legal Precedent MINCEY v. ARIZONA (U.S. Supreme Court, 1978) Drug bust that went wrong and an undercover police officer was killed. Police spent 4 days searching and seizing evidence Mincey arrested and convicted. Supreme Court ruled evidence collected was inadmissible because it was not from a proper search and seizure. Evidence taken without proper authority is probably not legally admissible

Michigan v. Tyler (U.S. Supreme Court, 1978) Building destroyed by fire was put out in early AM. Building left unsecured until 8 AM when a preliminary search was done (for cause of fire). Subsequent searches (at 4, 7, and 25 days) removed additional evidence. Tyler convicted of arson. However….Supreme Court overturned conviction. “…entry to fight a fire requires no warrant, and that once in the building, officials may remain there for a reasonable time to investigate the cause of the blaze. Thereafter, additional entries to investigate the cause of the fire must be made pursuant to the warrant procedures”