Roles Responsibilities and Myths Flashcards
Objectives of the Scene Investigator
- discover and document evidence
- ID locations
- photography
- maintaining the chain of custody
Investigative Process Tiers
First: first responder
Second: detective
Third: CSI
Fourth: FS
Fifth: Courts
Priorities and roles of the First Responder
1: safety and wellbeing
2: preservation of life
3: preservation of scene
- requests detective, who is briefed a walks through
The CSI effect
Unrealistic expectations and improper practices portrayed in the media. Absence of evidence is not evidence of absence.
LOSER - first responder
- Listen to victims/witnesses
- Observe surroundings
- Search for witness/evidence/witnesses
- Evaluate scene
- Record info
Mechanical loss
evidence lost in the process of life saving
Locard’s Principle
Every contact leaves a trace
Securing the scene
- Firearms and ammo remain in situ
- bodies should remain untouched
- ASAP ID and preservation of transient evidence
- establish perimeters
Perimeters
- Outer: confines scene, overestimate
- Inner: specific target area
- Command Post:
- limit “official visitors”
Contamination and Safety
- loss, destruction or alteration of evidence
- pathogens, cross-contamination
- wash hands, use barriers, PPE
Sketching
Rough: done on scene, not to scale
Final: used in court, scaled and measurements
Mapping techniques
Baseline: measured along x-y line
Rectangulation: two baselines
Triangulation: measured from points x and y
Polar/Grid: angle and distance of a fixed point
Technology
- 3D scanner
- Structured light: bands of light
- Pulse based
- Phase based: signal bouncing off target
- used in reconstruction, expensive
