1. The Crime Scene “Oh, how simple it would have been had I been here before they came like a herd of buffalo and wallowed all over it.” A. Conan Doyle, The Boscombe Valley Mystery

2. Preserving the crime scene First officer on the scene First officer on the scene 1. Determines nature of crime 2. Gets medical assistance 3. Arrests as necessary 4. Secures crime scene – Crime scene tape – Barricade – Rope – Guards – Why is this important?

3. Witnesses Must be separated Must be separated Why? Why? Ask the following questions Ask the following questions 1. When did the crime occur? 2. Who called in the crime? 3. Who is the victim? 4. Can the perpetrator be identified? 5. What did you see happen? 6. Where were you when you observed the crime scene?

4. Primary and Secondary Crime Scenes Primary Primary Where the crime actually occurred Where the crime actually occurred e.g., bank in a bank robbery e.g., bank in a bank robbery Secondary Secondary Related to the crime but not where crime took place Related to the crime but not where crime took place e.g., getaway car, thief’s hideout e.g., getaway car, thief’s hideout

5. The Primary Crime Scene Includes Includes Spot where the offense took place Spot where the offense took place Entrance and exit (or escape) routes Entrance and exit (or escape) routes Locations of key pieces of evidence Locations of key pieces of evidence

6. Observing and Documenting the Scene Notes Notes Requires investigators to be observant Requires investigators to be observant May get details from people that might be overlooked May get details from people that might be overlooked Detail every step investigators take in order Detail every step investigators take in order Includes: date and time, weather, location, description of crime, names of people involved, etc. Includes: date and time, weather, location, description of crime, names of people involved, etc.

7. Documentation Photography Photography May capture details missed May capture details missed Special attention to points of entry and exit Special attention to points of entry and exit Taken at different angles Taken at different angles Close-ups Close-ups Ruler for scale Ruler for scale

8. Documentation Sketches Sketches Used with photography for perspective Used with photography for perspective Permanent record Permanent record Helps to note and remember details Helps to note and remember details Overall layout Overall layout Must give Must give date & time date & time scale scale reference points reference points distance measurements distance measurements investigators investigators victims victims suspects suspects legend legend

9. Documentation Video Video Another way to record and show details Another way to record and show details Allows for narration Allows for narration Begin outdoors and move indoors Begin outdoors and move indoors

10. Evidence Collection Searching the crime scene Searching the crime scene Systematic Systematic May require special lighting (for body fluids) May require special lighting (for body fluids) Method depends on Method depends on Size of area Size of area Complexity Complexity Location Location

11. Delicate Evidence Packaged first (bindle) Packaged first (bindle) Fingerprints Fingerprints Impressions (tool, tire, shoe) Impressions (tool, tire, shoe) Fibers Fibers Hair Hair Blood Blood

12. Packaging Separate labeled containers Separate labeled containers Liquids – unbreakable, airtight, sealed containers Liquids – unbreakable, airtight, sealed containers Moist – non-airtight containers Moist – non-airtight containers Clothing with trace evidence Clothing with trace evidence Some materials need to be frozen Some materials need to be frozen

13. Collection Methods Adhesive tape Adhesive tape Vacuum cleaner Vacuum cleaner Remove part of crime scene (e.g., wall, window frame) Remove part of crime scene (e.g., wall, window frame)

14. Evidence Controls From victim and/or suspect From victim and/or suspect Blood Blood Hair Hair From the crime scene From the crime scene Fibers Carpet Fabric Other materials

15. Securing Evidence 1. Allow evidence to dry if necessary 2. Place (dried) evidence on bindle paper 3. Fold bindle and tuck in top flap 4. Place in plastic evidence bag 5. Label and seal with tape 6. Collector signs name across tape 7. Attach chain-of-custody form

16. Chain of Custody Continuous record showing that evidence kept safe Continuous record showing that evidence kept safe Crime scene to court room Crime scene to court room To examine evidence To examine evidence Open bag at a place other than where originally sealed Open bag at a place other than where originally sealed Examine evidence Examine evidence Put back in bag and reseal Put back in bag and reseal Sign name across new piece of tape Sign name across new piece of tape Complete chain-of-custody form Complete chain-of-custody form

17. Crime Reconstruction Ultimately Ultimately Documentation Documentation Evidence Evidence Analysis Analysis Required in order to reconstruct the crime Required in order to reconstruct the crime Determine possible motive Determine possible motive “Let the evidence speak” “Let the evidence speak”

18. Remember Our ability to observe all of the details of our surroundings is flawed. Our ability to observe all of the details of our surroundings is flawed. We are naturally inclined to filter out unimportant information We are naturally inclined to filter out unimportant information We are naturally inclined to interpret what we see, look for patterns We are naturally inclined to interpret what we see, look for patterns Our memories are faulty Our memories are faulty Examine systematically Examine systematically Consciously decide to observe everything; turn off filters Consciously decide to observe everything; turn off filters Don’t jump to conclusions. The more information, the better the interpretation Don’t jump to conclusions. The more information, the better the interpretation Write everything down, photograph, sketch, document Write everything down, photograph, sketch, document