French forensic science pioneer Dr. Edmond Locard formulated the basis for all forensic science with his quote “Every contact leaves a trace.” This has become known as Locard’s exchange principle, which Kirk further detailed and expressed as: Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. While physical evidence “does not forget,” it can be degraded or contaminated by the environment or, more importantly, misinterpreted by humans. Moreover, the measurements on the evidence may not be sufficient to uniquely distinguish it from multiple sources. Most early analyses of forensic glass evidence examined how glass physically broke. While the glass fragments of interest were recovered from a broken window and the suspect’s briefcase, other control fragments were obtained for comparison.