The Crime Scene
The location & surrounding
areas where a crime has been
committed
Any & all objects that:
establish a crime link a crime to its victim link a crime to its
perpetrator
Must be recognized at scene & preserved!!
PPSCRIPT
Get medical help for those who need it
Arrest suspect
Keep out all unauthorized people
Rope off, barricade, station guards
The unaltered scene so don’t move a thing!!
Crime scene & adjacent areas From all angles & overviews
Body position & location
Close-ups of evidence, injures, weapons
Place ruler by object for reference
A. Rough Sketch
shows evidence & important features
use tape measure distances must be
measured from 2 fixed points (walls)
B. Finished Sketch
very accurate & drawn to scale
drafting tools & computer programs used
Systematic & thorough
Establish points of entry & exit
Victim’s body is also searched at autopsy
Avoid contamination!!!
Keep in original condition
Bloodstains scrape off surface transfer to moist
swab cut out stain
1. Victim’s clothing2. Fingernail scrapings3. Hair4. Blood (DNA)5. Vaginal, anal, & oral swabs (sex
crimes)6. Recovered bullets from body7. Hand swabs (gunshot residues)
Sample of known origin (control)
Compare it to crime scene evidence
Ex: Paint from suspect’s car & paint found on victim
1. Latex gloves (doubled) & shoe covers
2. Masks / goggles / face shield / coveralls
3. Biohazard bags & labels4. Contaminated equipment
disinfected with 10% bleach solution
5. No smoking, drinking, or eating
Detailed written description of crime scene & evidence
Provide time & person who found evidence
Document everything you see!!!
Label/Tag officer’s initials location it was
found time
Establish Chain of Custody
A.K.A. Continuity of PossessionA list of every person the evidence
was passed on to Transfer of evidenceFailure to establish this may lead
to questioning of the authenticity and integrity of evidence.
Evidence must be packaged separately
The following items are useful: forceps manila envelopes unbreakable containers/pill bottles with lids screw-cap glass vials
Use airtight containers b/c they trap fumes
Do not use airtight containers
Place in paper bags to dry
Transfer to crime lab in BIOHAZARD bags
Send evidence to lab for analysis
Chain of Custody must be included Keep it short!
Hand delivery is best
ProtectPhotograph
SearchCollect
RecordIdentify
Package
Transport
Search and Seizure
Warrants
Mincey v. Arizona
Michigan v. Tyler
Drug dealer undercover cop killed
4-day search at homicide scene
No warrant
Guilty verdict reversed
Business fire search conducted morning after
3 other searches (4,7, & 25 days later)
No warrant
Guilty verdict reversed
Protects against unreasonable searches & seizures
Warrants must be obtained when time & circumstance permit it
It’s an emergency!
You’re being arrested!
You give your permission!
Evidence is in danger of destruction!