U.K. researchers are developing a coating for bullet casings that sticks to the hands (or gloves) of anyone handling it and is very difficult to remove. The idea is to give each bullet a "fingerprint" that can be traced to a given crime.

Today, cops rely on generic gunpowder, primer and lubricants getting on the shooter's hands and clothing when a bullet is fired. Such techniques can tell when someone has fired a gun, but can't tie a shooter to a specific bullet casing.

The new coating is made from chemicals infused with nano-sized particles 30 microns in diameter (one micron is one millionth of a meter).

Each coating can have a slightly different chemical composition to give it a unique signature that can help establish a link between a fired cartridge and a shooter, according to University of Surrey chemistry professor Paul Sermon, who led a team of colleagues from other universities with more than $743,000 in funding from the Engineering and Physical Sciences Research Council (EPSRC), the U.K.'s main agency for funding research in engineering and the physical sciences.

In addition to the coating, the researchers are also experimenting with bullet casings made with a micro-patterned pyramid texture able to retain dead skin cells--and with it, DNA evidence--from a thumb as it loads a cartridge into a firearm. Law enforcement has a difficult time extracting DNA or prints from bullet casings due to their smooth, shiny surfaces. Generally, efforts by law enforcement in the U.K. to use DNA evidence from gun cartridges are only successful about 10 percent of the time, according to Sermon.

Sermon says both the nanotag and DNA capture technologies could be available for use within a year, adding that he and his team are currently focusing on understanding the precise requirements of the police and cartridge manufacturers.

Of course, gun violence in the U.S. is a whole different animal. Whereas England's Home Office reports a total of 21,521 offenses involving firearms committed in England and Wales in 2005 and 2006, the U.S. Bureau of Justice Statistics' National Crime Victimization Survey (NCVS) in 2005 reports that 477,040 victims of violent crimes in the U.S. stated that they faced an offender with a firearm.

*Image courtesy of the Engineering and Physical Sciences Research Council