High Quality Content by WIKIPEDIA articles! Trace evidence is evidence that is discovered by finding minute quantities of objects on other objects. These materials often transferred by heat induced by contact friction. The importance of trace evidence in criminal investigations was shown by Dr. Edmond Locard in the early 20th Century. Throughout the past century, forensic scientists have used trace evidence to reconstruct crimes, as well as to describe the people, places and things involved in them. Case studies of real life homicides have been published in the forensic science literature showing how trace evidence has been used to solve these crimes, free the innocent, and bring the guilty to justice. Trace evidence is also important in accident investigation, where movement of one part against another will often leave a tell-tale mark. Such analysis is of great use in forensic engineering.