21 terms

Processing the Crime Scene

STUDY
PLAY
First Responders
-Safety first
-Secure the scene
keep witnesses separate
Primary Crime Scene
site of crime
Secondary Crime Scene
related to the primary scene
Processing the Scene
1. Preliminary walk through
2. Documentation
3. Detailed search
4. Packaging
5. Preservation
6. Scene Reconstruction
Preliminary Walk Through
- be curious
- be skeptical
- identify scope of crime scene
Documentation
- photo
- notes
- video
- sketches
Photos
- pictures with ruler
- picture without ruler
- unnarrated video
- # of all evidence
Notes
- very detailed
- need to make sense years later
Video
- do not add sound
- do not edit
- do not interrupt once you have started taping
- general to specific
Sketches
- most important role: measurements, scale, relative placement
- include date and time; scale; reference points; distance measurements; name of investigators, victim, suspects, and a legend
- original sketch = evidence cannot be changed
- rough sketch at scene, final sketch later
Detailed Search
- line or strip
- grid
- sone or quadrant
- wheel, ray, spiral
Packaging
Collect physical evidence
- can be anything from massive objects to microscopic traces
General Rules for Packaging
- package fragile first (fingerprints)
- send whole articles of clothing
- use forceps, pill bottles, envelopes, vials
- druggist fold
- do NOT put bloodstains in airtight containers
- DO put charred fire debris with possible accelerants in airtight container
Blood and Semen Stained Clothing
- paper bags - recommended
- bloodstains - scrape, transfer to a wet swab, cut out
Druggist Fold
paper bindles are commonly used for storage of trace evidence like hairs, fibers, etc
- seal w/ tape
Package Delivery
submit to lab for testing
- personal delivery
- mail
Controls
- a control is a standard/reference same for comparison to evidence
- it is physical evidence whose origin is known, like blood or hair from a suspect, that can be compared to crime scene evidence
Examples of Control
- control paint from suspect vehicle in hit and run
- control hair from victim/suspect
- control blood or cheek swab from victim/suspect
- control (unburned) samples of wood or carpet
Preservation
- secure area
- chain of custody
Chain of Custody
- a written record of all people who have had possession of an item of evidence
- case number
- description
- initials
- date
- time
- location
- evidence number
Scene Reconstruction
- hypothesize the likely sequence of events using:
- shoe prints
- fingerprints
- tool marks
- blood
- bullet trajectories
- body