PHYSICAL EVIDENCE MANUAL - Crime Scene Investigator Network

Physical Evidence Manual
Adopted: May 2002
Revisions: 6
Last Revision: January 31, 2008
13.0 GLASS EVIDENCE
Glass is one of the more important types of physical evidence that is commonly
overlooked. Glass is frequently encountered in burglaries and hit and run cases,
and glass fragments may be found adhering to garments, shoe soles, or other
property belonging to the suspect(s) as well as in hair combings.
Glass evidence cannot be individualized to a single source, however, there are
some instances where two fragments can be physically matched together and a
common origin can be conclusively established.
Glass examinations may reveal the following:
• Whether or not evidence glass is similar to glass from a known source
• The type of glass (e.g. tempered glass, container glass, etc.)
• The direction of force (from inside or outside) used to break a window
• The order of shots fired into a window or windshield
Consider that large glass pieces may have latent fingerprints present and the
broken edges of glass may have other trace evidence present such as blood,
hair, or snagged fibers.
Collection and Packaging of Glass Evidence
• Collect and submit all glass pieces if you believe numerous glass pieces
were from the same object (e.g. a window, a bottle, vehicle headlights,
etc.) and request the laboratory to attempt a physical match.
• Package glass pieces from different locations into different containers,
clearly marking the outside packaging as to the location and description of
the evidence.
• Label large glass pieces with orienting marks (e.g. up/down,
inside/outside) when applicable.
Large Glass Pieces
Collect and package a large glass piece in a rigid container such as a cardboard
box. Protect the broken or fractured edges of the glass from any additional
damage or breakage.
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