External beveling of entrance wounds by handguns

External beveling of entrance wounds may be seen either when a bullet strikes the skull tangentially, producing overlapping entrance and exit wounds (keyhole defect) or, more commonly, in entrance wounds when the bullet strikes the skull perpendicularly to the surface of the bone. In the latter cases such external beveling may be partially or completely circumferential. The mechanism of producing beveling of an entrance wound when a bullet strikes the skull perpendicularly to the surface is not completely understood. Several proposed mechanisms are briefly discussed. The possible misinterpretation of an entrance wound as an exit wound is stressed. Such a misinterpretation should never occur when a complete autopsy is performed.