Volume 23, Issue 4 (October 1978)
Bullet Residue as Distinguished from Powder Pattern
It is often necessary to determine the distance and direction from which a gun was fired at an object. This is easily accomplished by observing the position and dimensions of any powder pattern deposited. The presence of a powder pattern usually indicates a close-proximity firing. A ease involving a rifle used to fire through a window and shade on a door was presented for such a routine investigation. Contrary to the initial opinions of the investigating officer at the scene, laboratory tests showed that the pattern was not a powder pattern but instead a lead residue appearing much like a powder pattern, yet having distinctive and reproducible characteristics, These lead residues can occur at long distances from the muzzle (that is, 9 m or 30 ft) and are always present on the opposite side of the target, if it is penetrated. Information regarding the case which lead to the investigation is presented. Equipment devised to reproduce the test is described, and photographs of the patterns produced are presented. Included are points of difference between conventional powder tattooing and the lead residue observed by us. Some discussion is given to the effects of varying distances, calibers, and bullet compositions.