EDX for Examination of Clothes

A less commonly used method of examining clothing in order to make range determination involves the use of energy dispersive x-ray (EDX). The edges of the entrance hole are analyzed for the presence of antimony, barium, lead, and copper. Multiple readings are taken at varying distances from this hole. Thus, readings will be taken at 1, 2, 3, etc., inches from the 12 o'clock position of the hole, followed by additional readings taken in a similar manner from the 3, 6, and 9 o'clock positions. The distribution of the metallic residue around the entrance hole can thus be mapped out in a semi-quantitative manner. This pattern can be duplicated on identical cloth, with the same weapon and type of ammunition. This procedure gives one an approximation of the range at which the wound was inflicted. Identical cloth must be used as differences in cloth can produce marked differences in the deposition of the metals. Use of the EDX has the advantage that it is nondestructive and extremely rapid with no preparation of the garment necessary. If desired, after examination with EDX, the garment can be submitted for analysis by the Modified Griess and/or the Sodium Rhodizonate test.

When rimfire ammunition containing only lead in the primer was fired at cloth, it was observed that one may detect antimony, barium, and lead. The source of the antimony and barium were deposits of antimony and barium in the bore of the weapon caused by previous firing of other rimfire ammunition that had these metals in their primers.

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