Chapter 3, Crime Scene Investigation.

1. Purpose of Crime Scene Investigation

• Recognize evidence

• Preserve evidence

• Document evidence

• Collect evidence

⚠ CSI is about preservation, not solving the case on the spot.

2. Securing the Scene

First responder responsibilities:

• Ensure safety

• Provide medical aid

• Secure scene boundaries

• Prevent contamination

Common mistakes:

• Too many people entering

• Not wearing gloves

• Moving items unnecessarily

3. Crime Scene Documentation

Notes

• Written observations

• Times, conditions, actions

Photography

• Overall → mid-range → close-up

• Before anything is moved

Sketches

• Show layout

• Include measurements

• Permanent record

4. Searching the Scene

Search patterns:

• Line/strip

• Grid

• Spiral

• Zone/quadrant

Choice depends on:

• Scene size

• Number of investigators

• Type of crime

5. Evidence Collection

Rules:

• One item at a time

• Proper packaging

• Label everything

• Maintain chain of custody

CHAPTER 3 TAKEAWAYS

• Documentation is just as important as evidence

• Contamination ruins cases

• CSI follows strict, repeatable procedures