Gun Shot and Blackening of Skin

     If a firearm is discharged very close to the body or in actual contact, subcutaneous tissues over an area of two or three inches around the wound of entrance are lacerated and the surrounding skin is usually scorched and blackened by smoke and tattooed with inherent grains of gunpowder or smokeless propellant powder. The adjacent hairs are blackened and the clothes covering the part are burnt by the flame.  If the powder is smokeless, there may be a greyish or white deposit on the skin around the wound.  If the area is photographed by infrared lights, smoke also around the wound may be clearly noticed.  Blackening is found if a firearm like a shotgun is discharged from a distance of not more than three feet and a revolver or a pistol is discharged within about two feet. (Modi’s Medical Jurisprudence and Toxicology)