ABSTRACT
Like impression evidence, glass is an important class of associative evidence found in multiple crime types. From the smallest of splinters to a window with bullet holes, glass is evidence that tells a story about its relationship to the crime. Assume a burglar wants to rob a house. He looks around and figures out that a particular house is alarmed but that the basement windows are not. Perhaps, the owners decided that the basement did not need an alarm system, rationalizing that the windows were too small for someone to crawl through. Perhaps, it was because of financial constraints. The burglar thus breaks a window in the basement and climbs through. Inadvertently, he is providing tangible evidence of the crime and is creating a potential source of evidence that could lead to his conviction, if caught. Although he might leave other evidence, the broken glass can provide investigative information, such as the direction of the break and the location of the entry point of the burglar. The glass itself is also important. For example, maybe the robbery had been staged by the people living at the house. Inspecting the glass in such case will reveal the direction of the break, outside-in or inside-out. If the break had been inside-out, it narrows the possibilities to two, assuming the window had not been broken prior to the burglary: (i) the people living in the house broke the window to stage the burglary, or (ii) this was how the burglar left the house.
