A New Technique for Detecting Gunshot Residue

The ability to determine whether an individual has fired a firearm is of great significance in the investigation of both homicides and suicides. When the bullet emerges from the barrel of the gun, it is accompanied by a jet of flame, gas, powder, soot, primer residue , metallic particles stripped from the bullet, and vaporized metal from the bullet and cartridge case. These lead to what we know as Gunshot residue (GSR). The most widely used primer compositions contain a mixture of lead, antimony and barium. However, in the mid-1990s, cartridges free of all three metallic elements, primarily because of the threat posed by the 'Lead' constituent of the bullet to the environment as well as to the person firing the weapon due to the gases emitted during discharge of the firearm were introduced in some western countries. However, the availability of such type of ammunition posed a difficulty from the forensics point of view in detection of usual constituents of GSR i.e. lead, antimony and barium from the generally employed tests mentioned above. To deal with the problem of this new “eco-friendly” type of ammunition a new technique is under research called solid phase micro-extraction called as the 'Burleson Test' which can use a tiny amount of residue and uses a new method that can even identify components in newer eco-friendly ammunitions that do not contain lead or the metals other tests used for identifying residue.