How can comparison of glass fragments help in CSI?

How can comparison of glass fragments help in CSI?

Richard Saferstein (Former Chief Forensic Scientist) gives expert video advice on: How is the analysis of glass used in CSI?; What are the different kinds of glass studied in CSI?; How can comparison of glass fragments help in CSI? and more...

Glass is typically class evidence and it is used to link a perpetrator to a crime scene. So if a crime scene, for example, occurs with the breaking of glass, and there is some piece of glass, or pieces of glass that are found in the possession of the suspect/perpetrator, the crime lab will attempt to compare those pieces of glass to the broken window at the crime scene. And this comparison is typically carried out by looking at the density and the refracted index characteristics of glass, matching them and comparing them to one another.