6. Searching for Evidence

1. 6. Searching for Evidence • Must be thorough and systematic • How the search is carried out depends on the location and size of the area and the actions of the suspect(s) and victim(s)

3. Typical types of Crime-Scene Searches Spiral Search Method: Begins from one point of the crime scene and continues in a spiral fashion to another point

4. Typical types of Crime-Scene Searches • Strip or Line Search: Several investigators begin side-by-side and search in a straight line and turn around and continue back on an adjacent part of the area

5. Typical types of Crime-Scene Searches • Grid Search: Investigators begin a search in an S-pattern from the a border of a crime scene and overlap the S-pattern on return

6. Typical types of Crime-Scene Searches • Quadrant or Zone: A small area or room is searched. It is broken down into zones and search one by one.

7. 7. Securing and collecting evidence All evidence needs to be properly packaged, sealed and labeled.

8. Integrity of Evidence • Each different item or similar items collected at different locations must be placed in separate containers • Prevents damage • Prevents cross-contamination of specimens

9. Packaging Evidence • Use airtight containers for charred evidence from fires (arson): • Prevents evaporation of accelerant • Common packaging: • Empty, unused paint cans • Tightly sealed jars

10. Packaging Evidence • Use wrapping paper, manila envelopes, paper bags are used for blood stained material • Airtight containers are never used because they can readily grow molds and destroy evidence • Airdry wet/bloody clothing and place in paper bags

11. After damp items have air-dried, you should place them in a paper bindle also known as a “druggist fold”. • They can then be placed in a plastic or paper container.

13. Items should all be sealed with tape and labeled with the signature of the collector written across the tape. • An evidence log and chain of custody must be attached to the evidence container.

14. Chain of Custody • A list of all persons who came into possession of an item of evidence • May include: collector, carrier, lab tech, evidence storage officer, investigator, medical examiner, etc • Unnecessary personnel should not handle evidence without justification prevents contamination

15. Standard/Reference Samples • Physical evidence whose origin is known, such as blood or hair from a suspect, that can be compared with crime scene evidence • Used as a comparison method to incriminate or exonerate a suspect or to identify a victim

16. Evidence Submission Form

17. Crime Scene Safety (Don’t write these yet…) • Increased risk of AIDS and Hepatitis B infection to responding officers at a crime scene • Precautions must be taken for officers to protect themselves from all types of hazards

18. Crime Scene Safety: Ways to Reduce Risks • 1. Wear double gloves, protective footwear and clothing • 2. Use masks/respirators, goggles or face shields • 3. Be alert to sharp objects such as knives, needles, razor blades, etc. • 4. Dispose of contaminated objects such as soiled gloves and clothing items that were worn by personnel

19. Crime Scene Safety: Ways to Reduce Risks • 5. Complete note-taking with uncontaminated gloves to prevent contamination of pens and notebooks • 6. Remove torn or contaminated material and discard immediately • 7. No eating, drinking or smoking at the scene • 8. All non-disposable linens or clothing should be labeled and laundered properly

20. Legal Considerations at the Crime Scene • All removal of evidence from a person or from the scene must conform to the Fourth Amendment: The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, 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.

21. Warrantless Searches • Existence of emergency situations • Prevent the immediate loss or destruction of evidence • Search of a person or property following a lawful arrest • Search by consent

22. Mincey v. Arizona • After an undercover narcotics officer was shot and killed, officers continued to search the scene for three days. They collected lots of evidence and Mincey was convicted of murder. • The court later ruled that the evidence was inadmissible due to no search warrant being obtained. The conviction was overturned and Mincey was set free.

23. Michigan v. Tyler • Fire destroyed a building and evidence was collected the first day at the scene. Evidence indicated the fire was set on purpose. After the initial entry, later entries into the building produced evidence. All evidence from later entries to the property were deemed inadmissible in court.

24. Analyze the evidence • After the crime-scene investigation, evidence can be sent to the lab for testing. • The FBI crime lab is the largest in the world.