The purpose of the sampler is to obtain gunshot residue samples from persons suspected of recently discharging a firearm. The residue consists of sub-microscopic particles and can be deposited on the shooter's hand, face, clothing, or hair, in varying amounts depending on the type, calibre, and condition of the weapon or ammunition used, as well as the environmental conditions at the time of the shooting. The basic elements of a sampler are a vial containing an adhesive soated aluminum stub mounted on a moulded rubber stopper. The adhesive has been applied to leave a bare portion on the stub for SEM operator identification codes(if neccessary) and to provide an area for electrical contact for an evaporated carbon coating. The aluminum stub is precision machined to very close tolerances so that multi-stub examination may be made in the SEM without refocussing and to facilitate automatic examination and analysis. The moulded rubber stopper has been designed to make an effective airtight seal to the clear plastic vial. As well, it has been designed so that the investigator's hand, while using the sampler, does not come into contact with the adhesive surface. The stopper is flexible over a wide range of temperatures. A pair of special 'Earwig' Tweezers may be used to pick up the stub easily.

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