8127/frame/fm

 
At the crime scene
 
What? | When? | Where? | Who? | How? | Why?
 
We see what we want to see
 
Recognition
and 
 
detection
of evidence
 
Goals of Evidence Collection
•Maintain physical integrity
•Limit degradation
•Prevent contamination
 
Contamination:
Any substance inadvertently introduced into or
onto an item of evidence after its recognition by a responsible party.
 
If you don’t ask the right question, 
you won’t get the right answer, 
no matter how brilliant your analysis.
 
The Processes of Criminalistics 
 
Identification
Defining the physicochemical nature of an evidence item.
 
Classification
Inferring multiple potential common sources for an evidence item.
 
Class Characteristics
Traits
 
 
that are produced by a controlled process. They are used to
group like objects into sets.
 
Individualization
 
Concluding a singular common source for two items
 
Individualizing Characteristics
Traits that are produced by a random, uncontrolled process. They
are used to individualize items to a common source.
 
Association
An inference of contact between two objects, the source of the evi-
dence, and the target on which it was found.
 
Reconstruction
The ordering of events in relative space and time based on the physical
evidence.
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Appendix F
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