Also, I've conducted hundreds of tests for gunshot residues (GSR) on clothing and other materials. Tests are conducted at the firing range by test firing the evidence firearm and evidence ammunition involved in the shooting incident at different distances into test materials as similar as possible to the evidence garment or material. If these items are unavailable for some reason the exact same type of firearm and ammunition may need to be substituted to duplicate as closely as possible the results expected with the evidence firearm/ammunition/material combination. The photographs below show some of the patterns expected with a given firearm/ammunition combination at a given distance.