Microstamping helps solve that problem. Lasers etch the microscopic code onto the firing pin of each gun during the manufacturing process. Then, even in the absence of a retrieved weapon, bullet casings found at a crime scene can lead investigators back to the gun's last legal owner.
Opponents say the technology, invented by an NRA member in the 1990s, is unproven and may be defeated by filing the firing pin. But authorities, notably in California, feel otherwise.
In May, California's Attorney General Kamala Harris enacted a law requiring microstamping on all guns sold in the state. The law had been signed by Governor Arnold Schwarzenegger in 2007 but implementation was delayed by challenges from gun rights organizations.
Quoted by the San Francisco Chronicle, Harris said, "The patents have been cleared, which means that this very important technology will help us as law enforcement in identifying and locating people who have illegally used firearms."The New York State Assembly passed a similar bill yet to be approved by the state Senate. Other states are considering similar measures. A bill containing a federal requirement for microstamping was introduced in Congress in 2008 but died in committee. Microstamping will add to the manufacturing price, but studies show it could be implemented for under $10 per gun the first year and far less thereafter. Like any technology, too, its effectiveness will likely be improved as implementation and research expand. Importantly, the technology puts no other limitations on private gun ownership. It is invisible and does not affect the use of a weapon. The most vocal critics have claimed it will push manufacturing out of states where it is required, resulting in an effective ban on guns in those states. Some smaller makers have withheld the sale of weapons in states that restrict private ownership. Larger manufacturers, like Glock and Smith & Wesson (SWHC - Get Report), are unlikely to join them, in particular because of the potential loss in sales to law enforcement. Obviously microstamping in one state won't help for illegal weapons purchased elsewhere, but it's a start. If more states express interest in this technology, gunmakers might be encouraged to make it a national standard, handing investigators in all states an important new tool while discouraging potential straw buyers. -- Written by Carlton Wilkinson in New York City. Follow @CarltonTSC