Trace evidence

From Freepedia

Trace evidence is evidence that is found at a crime scene in small but measurable amounts. Examples of typical trace evidence include hairs, fibers, soils, botanical materials, gunshot residue, explosives residue, and volitile hydrocarbons (arson evidence). The most common instrument used in trace evidence analysis is the compound polarized light microscope. Gunshot residue may be identifed by elemental analysis using an atomic absorption spectrophotometer or with a scanning electron microscope. Small amounts of explosives, volitile hydrocarbons, and other chemicals are identified with the use of analytical instruments, such as gas chromatography, mass spectrometry, and infrared spectroscopy.