Glass Examinations

Glass comparison examinations can determine whether particles of glass originated from a broken source of glass. Glass fracture examinations can determine the direction and type of the breaking force and the sequencing of shots.

Submitting Glass Evidence

Questions concerning glass evidence should be directed to 03-9702366. Follow the Evidence Submission directions including Requesting Evidence Examinations and Packaging and Shipping Evidence.

Glass Comparison Examinations

• Submit samples of glass from each broken window or source in leakproof containers such as film canisters or plastic pill bottles. Avoid using paper or glass containers.
  
  

• Submit samples of laminated glass (such as a windshield) from each side of the laminate. Label the samples INSIDE and OUTSIDE and package separately in leakproof containers such as film canisters or plastic pill bottles. Avoid using paper or glass containers.
  
  

• Submit the victim(s)' and suspect(s)' air-dried clothing. Each clothing item should be packaged separately in a paper bag.
  
  

• Search for particles in the victim(s)' and suspect(s)' hair, skin, and wounds. Submit particles in leakproof containers such as film canisters or plastic pill bottles. Avoid using paper or glass containers.
  
  

• Search for particles in vehicles by vacuuming each section of the vehicle separately. Do not use tape for recovering glass particles. Submit vacuum sweepings in leakproof containers. Avoid using paper or glass containers.
  
  

• Do not process evidence for latent prints.

Glass Fracture Examinations

• Label the sides of the glass in the frame INSIDE and OUTSIDE. Label the glass where it was removed in the frame such as TOP, BOTTOM, LEFT, and RIGHT.
  
  

• Submit all glass pieces so that the pieces can be fitted together to identify the radial cracks near and at the point(s) of impact and to increase the probability of matching edges. Pack all glass separately and securely to avoid shifting and breaking during transport.
  
  

• Submit the entire piece of laminated glass, if possible. Secure the glass between plywood or sturdy cardboard. Do not place any objects into the impact area.
  
  

• Do not process evidence for latent prints.

 

Glass fractures produced by a low-speed impact such as a rock (top) and by a high-speed projectile such as a bullet (bottom).