PPT 1 Flashcards
what is evidence recovery
The recovery of physical evidence during investigations
The Role of the Criminalist
Assisting in the investigation
Probability of facts from physical evidence
Present & explain the evidence in courts
FSU officers give “Expert Testimony”
The Locard Principle
“Every Contact Leaves a Trace” or “Takes a Trace”
Trace Evidence:
Chance impressions examples
fingerprints & footwear
Trace Evidence: Physical match examples
Tool marks - Ballistics - Debris from Hit & Run MVC
Trace Evidence: Biology examples
DNA - Blood, Semen, Hair & Saliva - Blood Spatter Interpretation
Trace Evidence: Chemistry examples
Glass - Paint - Fibres
Forensic Services…
AFIS (Automated Fingerprint Identification System)
Vehicle Examination
Trace Evidence Collection
Blood Spatter
Scale Diagrams
DNA sample collection
NICHE (Digital Mugshot System)
Composite Drawings
Reenactments
still photography
video
SOCO Officer must have…
Specialized Training
Appreciate the How & Why of certain actions
The reasons for the examination of the physical evidence
Must have a keen sense of WHAT he may find and WHERE
What is Physical Evidence?
Any item that may yield positive proof of the guilt or innocence of a person with respect to a specific crime or occurrence
What may physical evidence do?
Corroborate a witness
Confirm or discredit an alibi
Identify a person or object to the scene
Help to establish a sequence of events
Why collect physical evidence?
To preserve evidence
To have evidence scientifically examined and/or compared to a known exemplar
To prepare the evidence for presentation
The Crime Scene Search
Must be methodical
Develop a style to be used at every scene
Glean info from first officers, witnesses and complainant
Be aware of contamination problems (by any of the above)
Keep an open mind
Organization of a Crime Scene Search
The perimeter (inside & outside)
The point of entry (POE)
The path of contamination
The object of the attack (point of focus)
The point of exit (POX)
Perimeter
In a major crime the wider the perimeter the better (easy to make smaller but difficult to make larger)
In a break-in you will often find attempted entry points on the building perimeter not found by others at the scene
Watch for footwear impressions & evidence leading up to the point of entry
Point of Entry (POE)
most common location of trace evidence
The culprit often spends considerable time at the POE (F/P, F/W, toolmarks etc.)
Often fresh handling is easier to notice at the POE (although we cannot testify to the age of a latent fingerprint impression)
Path of Contamination
This pathway could provide footwear impressions or other evidence handled or discarded by the culprit
Consider using an oblique light source during the search for footwear impressions and indications of fresh handling
Object of Attack
Point of Focus
The culprit may spend considerable time at this location
Eg. - Safe Job - may leave behind tools, cigarette butts, drinks etc.
Eg. - Sexual Assaults - the location of the attack is an area where biological evidence for DNA may be found
Point of Exit (POX)
The point of egress may reveal useful evidence
Often in the euphoria of a successfully completed crime or in a hurried departure the culprit(s) will become careless
The exit scene of armed robberies are often a good location to find POX evidence
Auto Examinations
Affected by atmospheric conditions (auto should be stored indoors, dry & warm)
Examine windows, mirrors, clean painted surfaces (door & roof edges)
Consider the trunk lid, hood, gas cover, and licence plates (Are they stolen?)
Examine items left behind in the stolen auto
