1. Crime Scene Investigation
Chapter 2

2. At the Crime Scene
The first person on the crime scene is usually a police officer. His first job:
Take care of emergencies.
Get medical attention for any victims
Disarm/arrest perpetrators.

3. Next, (s)he should secure and isolate the crime scene to prevent unauthorized access to the area:
Erect ropes or barricades
Position guards
Identify and Separate Witnesses

4. Record the Crime Scene Photography Crime scene should be unaltered
Entire area should be photographed, in addition to adjacent areas
Many angles should be used
Position and location of body and other evidence should be shown
Close-up pictures of injuries and weapons
Use a ruler to show size of an object
Videotaping is another option

5. Sketch This is a rough sketch
Should show accurate measurements, but need not be to scale
Must show all relevant evidence
Has a legend below drawing
Should have compass heading designating north
A finished sketch can be done later (using CAD software)

6. Notes Detailed written description of the scene
Location of items of evidence recovered
Describes who discovered evidence, who packaged evidence, where evidence went once packaged
Used to “refresh” investigators’ memories – often years after the crime.
Notes can be taped rather then written (they will have to be transcribed later).

7. Crime Scene Search
A systematic search for evidence must be planned and executed.
Types of search patterns
Spiral
Strip or Line
Grid method
Quadrant or Zone search
Evidence to be collected depends on the crime committed
Evidence that a crime was committed
Evidence of how the crime was committed
Evidence of who committed the crime

9. Collection and Packaging of Evidence
Avoid Contamination!
If possible evidence should be submitted intact (entire article of clothing, etc.)
Hairs, fibers, blood should not be removed from clothing
Trace evidence should be collected with forceps and placed in bottles, pillboxes, manilla envelopes, or screw-cap glass vials.
Bloodstained materials should NOT be stored in air-tight containers
Items from the scene of a suspicious fire MUST be stored in air-tight containers.

10. Chain of Custody
Every person who handled or examined evidence must be accounted for.
Everything must be carefully marked

11. Controls must be obtained
Samples for comparison
Test for Contamination
Test for match (suspect)

12. Safety and Legal Issues
Fear of AIDS and Hepatitis
Latex gloves and protective shoe covers
Particle mask and goggles if dust present
Anything that comes into contact with potentially infectious materials (fingerprint brushes, gloves, pencils, etc.) should be placed into biohazard bag
No eating, drinking, or smoking

13. Fourth Amendment guarantees against unreasonable searches and seizure.
Need a Warrant to search, except:
Emergency circumstances
Need to prevent immediate loss or destruction of evidence
Search of a person lawfully arrested
Consent of parties involved