The SEMOPTICS Gunshot Residue (GSR) Samplers and Kits offered by SPI Supplies are designed for Case Work and acceptance in courtroom settings. While they can also be used for investigative examinations, we want to stress that these GSR Samplers and Kits were designed specifically for police-type work. They have built into them of controls one would expect for this kind of application.

The purpose of the Gunshot Residue Kits is to obtain gunshot residue samples from a person 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. Residue amounts depend on the type, caliber, and condition of the weapon or ammunition used, as well as the environmental conditions at the time of the firearm discharge.


Components of the SEMOPTICS GSR Sampler:

The basic elements of a GSR sampler are a vial containing an adhesive coated 25 mm aluminum SEM “pin styled” mount set into a molded elastomeric (rubber) stopper. The adhesive tape on the SEM mount allows a total of 8 "tamps" or "samples" to be taken before the sticky surface begins to lose particles. Another double-sided conductive carbon adhesive, and only one or two "tamps" to be taken, resulting in far fewer particles collected and available for analysis. The larger 1" (25.4 mm) total area of the GSR Samplers, leaves the outside 10% of the tape to be not sampled, thereby reducing possible contamination from the investigator during the conduct of the sampling.

The metal used for the SEM mount is a special "forensic" alloy which means the alloy used is free of the important elements of GSR analysis. The alloy is assay certified from a chemical laboratory as to the actual composition of that particular batch of aluminum.

The molded elastomeric stopper has been designed to make an effective airtight seal to the clear plastic vial. It has also been designed so the investigator's hands while using the sampler, do not come into contact with the clean pristine adhesive surface. The stopper is flexible over a wide range of temperatures and for use in cold environments.

Each sampler and kit is uniquely numbered, (based on a date code). This allows for full documentation and traceability for each and every SEM mount that is analyzed for the GSR analysis.

A pair of special SEM Mount GSR Tweezers can be used to easily pick up the SEM mount.


Shelf life considerations and storage conditions:

The adhesive system used has been selected in part because of its long shelf life, which rated by the manufacturer of the adhesive to be 10 years when stored at room temperature. The powder-free vinyl gloves included with the kit are also warranted for 10 years.

Remember that all SEMOPTICS GSR Sampling units and kits are assembled under class 100 conditions using the latest technology in clean benches. The SEM mounts are also washed and dried under the same Class 100 conditions. From beginning to end of the process including final packaging, everything is done under Class 100 conditions.