Crime Scenes January 24, 2014
Why do we go to crime scenes?
Discover key evidence (for crime lab)
What is at a crime scence?
-evidece of events
-evidence from the suspect
Conclusive (thumbprints etc), circumstantial (little pieces together), interpretive (varies by
What are the steps?
General survey (walk through)
Overview photos and sketching (documentation)
Collection and preservation
What are the elements of the arrival?
Safety of responding personnel
Check the medical condition oof the victim
Prevent loss of evidence due to medical aid, suspect action, and environmental issues (wind,
rain, snow heat)
Stabilization of the scene?
Insure suspect is or isnot present
Remove all personas from the scence
Protect perishable evidence like sho/tire imprints, fingerprints, GSR (gun shot residue
Isolate the participants Effects of weather (rain etc)
How to crime scene security?
Use tape or guards
Purpose is to restrict access to select few
Log who enters and leaves the scene
How to set boundaries?
Better to overestimate (but w/in reason)
Consider entry and exit (routes)
Focus on 3 dimensions (major scenes can have airspace closed)
How to assess the crime scene?
-who needs to be notified: supervision, coroner, crime lab, sheriff, specialized assistance
Determine what is critical for immediate processing/set priorities
What goes on in processing the scene?
90% of time in documentation
Photos, video, fingerprints, note taking, bagging and tagging evidence collector, security,
Limited it one or 2 ppl
Note likely entry and exit points
Note misplaces, foreign objects
Not locations of prints trace
Designate trash areas, commence center, smoking areas, equipment areas
Where is the command center (admin of crime scene, sometimes held at neighbors house),
restrooms, food/drink, phones (or anything that can be listened to) If night is approaching, how much will be done,
Order of processing
Photography, sketches, and note taking.
How to Search and locate evidence?
Flag entry areas
Mark, record, collect
Packaging and labeling
Order of collection (trace evidence, then biological evidence, then fingerprints, then references)