Chapter 2 The Crime Scene

Crime Scene The location & surrounding areas where a crime has been committed

Physical Evidence 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!!

Processing the Crime Scene 1. Preserve Life 2. Protect Area 3. Photograph 4. Sketch 5. Notes 6. Search 7. Collect 8. Package 9. Chain of Custody

Step 1: Preserve Life Get medical help for those who need it Arrest suspect

Step 2: Protect Area Keep out all unauthorized people Rope off, barricade, station guards

Step 3: Photograph The unaltered scene  so don’t move a thing!! Crime scene & adjacent areas From all angles & overviews

Photographs continued… Body position & location Close-ups of evidence, injures, weapons Place ruler by object for reference

Step 4: Sketches A. Rough Sketch  shows evidence & important features  use tape measure  distances must be measured from 2 fixed points (walls)

Sketches continued… B. Finished Sketch  very accurate & drawn to scale  drafting tools & computer programs used

Step 5: Notes Detailed written description of crime scene & evidence Provide time & person who found evidence Record who & how it was packaged  where it was sent

Step 6: Search Systematic & thorough Establish points of entry & exit Victim’s body is also searched at autopsy

Step 7: Collect Avoid contamination!!! Keep in original condition Bloodstains  scrape off surface  transfer to moist swab  cut out stain

Step 8: Package Evidence must be packaged separately Label/Tag  officer’s initials  location it was found  time

Packaging Continued … The following items are useful:  forceps  manila envelops  unbreakable containers/pill bottles with lids  screw-cap glass vials

Packaging Fire/Arson Evidence Use airtight containers b/c they trap fumes

Packaging Wet Bloodstained Materials Do not use airtight containers Place in paper bags to dry Transfer to crime lab in BIOHAZARD bags

Step 9: Chain of Custody Transfer of evidence A list of every person the evidence was passed on to Keep chain as short as possible

What should be collected? 1. Victim’s clothing 2. Fingernail scrapings 3. Hair 4. Blood (DNA) 5. Vaginal, anal, & oral swabs (sex crimes) 6. Recovered bullets from body 7. Hand swabs (gunshot residues)

Standard/Reference Samples Sample of known origin (control) Compare it to crime scene evidence Ex: Paint from suspect’s car & paint found on victim

Crime Scene Safety 1. Latex gloves (doubled) & shoe covers 2. Masks / goggles / face shield / coveralls 3. Biohazard bags & labels 4. Contaminated equipment  disinfected with 10% bleach solution 5. No smoking, drinking, or eating

Court Cases

Mincey vs. Arizona Drug dealer  undercover cop killed 4-day search at homicide scene No warrant Guilty verdict reversed

Michigan vs. Tyler Business fire  search conducted morning after 3 other searches (4,7, & 25 days later) No warrant Guilty verdict reversed

4 th Amendment Protects against unreasonable searches & seizures Warrants must be obtained when time & circumstance permit it

A Warrant is NOT Needed When: It’s an emergency You’re being arrested You give your permission Evidence is in danger of destruction