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

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!