What type of evidence is glass?
Glass – Glass can be used to gather evidence, for example collecting fingerprints or blood from a broken window; however, glass also has a place in the trace evidence section. Broken glass fragments can be very small and lodge in shoes, clothing, hair or skin.
What is a glass fracture?
When the tempered glass breaks it breaks into tiny cubes with no sharp edges. … Other types are- Wire glass, Colored glass, Light sensitive glass. Glass bends in response to any force that is exerted on anyone of its surfaces; when the limit of its elasticity is reached, the glass fractures.
How do you collect evidence from glass?
Place small glass fragments in paper bindles, then in coin envelopes, pill boxes, or film cans which can be marked and completely sealed. Place large glass fragments in boxes. Separate individual pieces with cotton or tissue to prevent breakage and damaged edges during shipment. Seal and mark the box containing them.
Why is glass important in forensic science?
If a window or glass object is broken or shattered by a projectile, such as a bullet, the breakage pattern can be analyzed to possibly determine the angle of trajectory of the projectile, shedding more light on the crime, such as where the suspect was when the gun was fired.
What is tempered glass forensics?
Glass that has been subjected to extreme temperatures or chemical treatments to improve its strength is called tempered glass, or safety glass. Tempered glass is stronger than normal glass due to rapid heating and cooling.
What is glass analysis?
Glass analysis includes determining the type of glass based on glass fragments. … Basic properties, such as color, thickness, and curvature, can also help to identify different samples of glass just by looking at them. Optical properties, such as refractive index (RI), are defined by various manufacturing methods.
What are the characteristics of glass?
The main characteristics of glass are transparency, heat resistance, pressure and breakage resistance and chemical resistance.
What type of crimes would lead an investigator to look for glass fragments?
Purpose The value of glass fragments as evidence is not always fully recognized. Windows, automobile glass, broken bottles, and other glass objects may be crucial evidence in burglary, murder, hit-and-run and many other types of crime.
How are footprints collected at a crime scene?
Tire tracks can be found in snow, mud, dirt, or sand, or even on a victim at a crime scene. These tracks can be collected by photographing, casting, lifting, and/or collecting the clothing from the victim.