Crime Scene Investigation

1. Crime Scene Investigation Points to Know

2. Highlights • The first responder must secure the scene • All unauthorized personnel must be excluded from the scene • You secure a scene so that evidence won’t be rendered valueless • Lead investigator assigns tasks • Forensic scientist’s role begins at lab.

3. Recording a scene • Photography • Close ups and overviews • The scene, the evidence and surrounding areas • Sketches • Rough Sketch • Final Sketch • Notes • Description, location of evidence, time items were discovered, who discovered the item, Packaging of item and disposition of items

4. Searches • Spiral • Line • Grid • Quadrant/Zone • How to proceed depends on: • Location • Size • Actions of suspect and victim

5. Collect and package • Prevent a change in the evidence. • Contamination, breakage, evaporation, loss, careless packaging. • Attempt to keep the item on the item that bears it.

6. Collection • Trace evidence – not readily apparent to the naked eye. • Evidence is best maintained in its original state. • Each item collected must be placed in a separate container • Pill bottles, Manila Envelopes, Vials, evidence bags • NO regular envelopes

7. Collection Containers • Blood evidence = airtight containers • Because moisture = mold • Charred debris from arson must be in an airtight container. • Prevents evaporation of petroleum residues.

8. Chain of Custody • A list of all persons that have come into contact with the evidence

9. Obtain Standard Or Reference Samples • Compare evidence with a known/reference sample. • Blood evidence accompanied by a Whole Blood or buccal swab

10. ETC. • Prevent disease transmission • Get a search warrant.