Crime Scene Investigation Chapter 2 At the Crime

Crime Scene Investigation Chapter 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.

• 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

• 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

• 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)

• 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).

• 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

• 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.

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

• Controls must be obtained – Samples for comparison • Test for Contamination • Test for match (suspect)

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

• 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