Forensic science is often asked to demonstrate any physical link between suspect and firearm or tool. Ferrotace from Mistral Security has the ability to make this link by detecting trace amounts of ferrous metal on skin, even to the point of outlining the metal object on the skin (e.g., gun handle or grenade). The chemical reaction between the ferrous metal residue and Ferrotrace creates a purple colored corollary that is in the pattern of the object that was held in the hands.