Page 9 - Strands of Evidence Hair And Fiber
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Hair and Fiber
Analysis
hysical evidence results from the transfer of The exchange of physical evidence was first
small quantities of material – such as hair, described by Sir Edmond Locard. Locard’s
Ppaint chips, glass fragments, gun shot residue, principle states that “with contact between two
etc. – from one source to another and is most items, there will be an exchange.” When a crime is
often used to shed light on the events of a crime committed, material will be mutually exchanged
rather than to positively identify a criminal. Physical between the perpetrator and the crime scene.
evidence can be classified into two categories: Given this principle that “every contact leaves
a trace,” it is up to the investigator to identify
materials that are seemingly foreign to the
Individual characteristics: those that location.
identify a single source, like DNA
The amount of physical (or “trace”) evidence
Class characteristics: those that are transfered depends on the nature and duration of
associated with a particular characteristic contact, as well as the type of contacting surfaces.
but not necessarily an individual, such as Trace evidence transfer is more likely to be found in
blood type.
intimate, brutal crimes occurring over a long period
THE MYSTERY OF LYLE AND LOUISE 9
