1. The Crime Scene
Chapter 2
Beginning of new chapter

2. The Crime Scene
Physical Evidence – an object that can establish a crime has been committed or can link a crime and its victim or its perpetrator
massive objects or microscopic traces
First step is to recognize the presence of physical evidence

3. Securing the Scene Police usually the first responders: help or hinder
Priority to preserve life
Treat injuries
Move victims from danger
***Risk of contaminating or destroying evidence

4. Securing the Scene Secure and isolate crime scene
Remove non-essential personnel
Prevent traffic that could destroy evidence
Establish boundaries

5. Securing the Scene Remove suspects from the scene Detain eyewitnesses
To preserve evidence and avoid prejudicing eyewitness testimony
Detain eyewitnesses
Proper procedure: alone and separated from other witnesses

6. Preliminary Examination
Evaluate the scene
Perpetrator’s path of entry and exit
Initial walk-through
Limited amount of time to work a crime scene
Record the scene: photography, sketches, and notes

7. Photography Most important prerequisite: crime scene must be unaltered
Limited: people and money
Objects not to be moved until photos taken from all necessary angles
Photos show position and location of evidence
Close-ups record details
Size is significant: need reference point

8. Sketches Post-photography
Rough Sketch: Draft, essential info and measurements
Drawn at crime scene
Shows all recovered items of physical evidence
Other important features

9. Sketches Final Sketches: precise rendering of crime scene
Drawn to scale
Not done at crime scene
Concern for aesthetic

10. Notes Constant activity throughout processing
Include detailed written description of location where physical evidence is recovered
Time
Who
Position
How packaged

11. The Search Looking for the Evidence ~ thorough and systematic
Some evidence only detected in lab: important to collect carriers (vacuum sweepings)
Search pattern depends on size, location, and number searching

12. Beyond the Crime Scene Search for evidence extends to autopsy
Establish manner and cause of death
Tissues and organs sent for pathology and toxicology

13. Beyond the Crime Scene
Items collected from victim and sent to forensic laboratory
Clothing
Fingernail scrapings
Head/pubic hairs
Blood - DNA typing
Vaginal, anal, oral swabs (sex-related crimes)
Recovered bullets
Hand swabs ~ GSR analysis

14. Packaging the Evidence
Separate containers prevent contamination
Submitted intact – not removed from garments, weapons, etc. (precarious, large structures)
Tools: Pill bottles, glass vials, manila envelopes, sealable plastic bags
Mailing envelopes bad 
Druggist fold
EXCEPTIONS
~ fluids (bloodstains, semen) dried, packaged in paper
~ Charred debris – sealed in airtight container

15. Chain of Custody List of persons who are in possession of evidence
Must be maintained at all times
Record location, date/time, who collected
Any transfer of evidence must be recorded ~ kept to minimum

16. Additional Samples
Reference Samples: Physical evidence with known origin to compare to crime-scene evidence
Blood, hair, fiber
Substrate control: uncontaminated material near area of evidence recovery
removes background (accelerants and arson)
Evidence submitted by personal delivery or mail (postal restrictions)
Proper forms

17. Forensic -ologies Pathology: The M.E. or coroner Forensic Anthropology
4 (5) types of death:
Natural, homicide, suicide, accidental, unexplained
Investigates unnatural, unexplained death
Rigor Mortis
Livor Mortis
Algor Mortis
Forensic Anthropology
ID skeletal remains
Forensic Entomology
Insect morphology – establish TOD