Firearms are involved in approximately two-thirds of all homicides in the United States. Handguns are used in the majority of cases. Examination of a gunshot wound enables determination of the range and direction of fire. Test firing of the gun in question with the type of ammunition that was used in a specific case provides for reliable determination of the range of fire. Patterns and amounts of the deposits of soot and gunpowder on the body and the victim's clothing are key factors in such determinations. The three primary ranges of fire include contact shots, when the weapon is fired with the muzzle in actual contact with the body, close-range shots, and distance shots. In contact shots the bullet hole in the cloth touching the muzzle is sometimes surrounded by a flat ring corresponding to the profile of the muzzle. In addition, small amounts of smoke deposits may be deposited on the wound edges, particularly in the absence of protective clothing. A close-range shot is one that is fired from a distance at which gunpower residue and particles of primer and small metal fragments may be identified around the bullet hole. As the distance between the muzzle and target increases, the pattern of particles on the target increases in diameter and the density of particle dispersion decreases. In a distance shot the gunsmoke will not reach the target. The direction of fire may be determined from the relationship of entrance to exit wounds, although internal deviation of the bullet must be considered. In addition, less common types of ammunition, such as fragible bullets, produce unique injury effects. The autopsy of a gunfire victim must include a description of clothing, findings regarding bullet wounds, external and internal evidence of injury, cause of death determination, and toxicological and serological analyses. The characteristics described for handgun fire, particularly those of close-range shots, are also observed in shotgun wounding. Shotgun exit wounds, however, are uncommon even in contact or close-range shots. Extensive photographs, three references, and sketches are included in the chapter. For related documents, see NCJ-69731-35 and 69737-47.