Analysis of gunshot residue (GSR). Display of the results from an analysis of GSR with an X-ray beam to produce this energy dispersive X-ray pattern (EDX). This reveals the elements present, seen as the peaks in the pattern. Peaks are labelled for lead (Pb), antimony (Sb) and barium (Ba). GSR is produced during the firing of a gun. Various materials are used in the explosive mix that fires a bullet, and these are ejected from the gun in a cloud of GSR. This is deposited on the hand and clothes of the person who fired the gun, and on the surroundings. An adhesive GSR stub is used to sample suspects for analysis. This positive result indicates that the suspect recently fired a gun.