Forensic Trace Analysis the analysis of paint, accelerants, glass or chemical debris. This type of evidence is most commonly involved in arson and vehicular homicides. Some forensic laboratories also consider the analysis of microscopic hair and fiber evidence part of the trace chemistry discipline.
Air samples or fire debris are often brought to the laboratory and analyzed for the presence of an accelerant, indicating an intentionally set fire. Trace chemical analysis can also be performed on debris from an explosion to determine which type of explosive may have been used. The forensic scientist will use a variety of instruments, including microscopes, x-ray diffraction, gas chromatography, infrared spectroscopy and energy dispersive x-ray micro-analysis.
Hit and run accidents often leave behind a transfer of paint or other chemical materials from one surface to the next. The forensic trace analyst is often asked to analyze the paint to determine the possible origin, including the make and model of the originating vehicle. If a suspect is identified, the analyst may need to compare the evidence sample to a “known” sample from the suspect vehicle to determine if the two samples “match”, and could share a common origin.
In addition to fire, explosion and paint debris, forensic trace analysis could include the chemical analysis of virtually any other type of evidence. This could include items such as duct tape, cosmetics, concrete, fabric, soil, and gunshot residue.