Trace evidence are items found in small amounts that can be analyzed. They may include such items as hair, fibre, glass, metal, paper, paint or botanical sources (e.g. soil, pollen, leaves).

	Paint Chip
	© R.C.M.P./G.R.C.

Paint can be liquid, chip or smears. Paint can be identified by colour, type, texture (glossiness, granularity, hardness, wrinkling, cracking, blistering and chalking properties), layer structure and composition. Once the information is gathered, it can be compared to databases where information is stored about many other types of paint. This way, one can find out details about the clues that have been found. Paint identification can be very useful for hit and run incidents. The victim and the crime scene may have small chips of paint left behind from the assailant's vehicle that can be taken into evidence. At the lab, the characteristics of the paint are noted and then entered into a database. The databases allow for comparisons of large amounts of data. A match of vehicle paint from the crime scene to that in the database may yield the make, model and year of the car in question which assists the investigating officer as well as the courts during the investigation.

	Gunshot Residue Particle on Top of Hair
	© R.C.M.P./G.R.C.

Hair: Comparison microscopes are used to see if a hair sample found at a scene matches a known sample. Examination of hair can also determine the animal family of origin, the body area of origin for human hairs and the method of removal from the body, as well as providing an indication of racial origin. Scalp hair can give the scientist the most information because it usually undergoes the most varied treatments (dying, curling, cutting, hairspray, etc...).

	Magnified Hair Sample
	© R.C.M.P./G.R.C.

Hair comparison is not conclusive and this is the reason why DNA methods may also be used. Since all nucleated cells in the body contain DNA, hair roots and roots sheaths may be used, and the amount of DNA may be amplified using a method called PCR. The DNA is then typed and a match may be found. The first 10 mm of the bottom of each hair may be used for the DNA testing because it contains the root sheath. Although it does not contain nuclear DNA, the hair shaft may be analyzed for mitochondrial DNA.