Identifying the firearm used in a crime is one of the biggest challenges for criminal investigators. But what if a shell casing picked up at a murder scene could immediately be tracked to the gun that fired it?
A technique that uses laser technology and stamps a numeric code on shell casings can do just that. But the technology, called microstamping, has been swept up in the larger national debate over gun laws and Second Amendment rights, and has not been implemented anywhere in the country.
"I think it is one of these things in law enforcement that would just take us from the Stone Age to the jet age in an instant," said Commissioner Frederick Bealefeld III of the Baltimore Police Department. "I just can't comprehend the opposition to it."
But legislation proposed in several states to require gun manufacturers to use the technique has met fierce opposition.
Opponents, including the gun industry and the National Rifle Association, argue that microstamping is ineffective and cost-prohibitive. By linking guns to their original purchasers, they say, it unfairly targets legal gun owners, when the guns used in most crimes are illegally obtained.
The issue has become so heated that, in New York, where the state Assembly was debating a microstamping bill last week, one gun maker, the Remington Arms Co., threatened to pull its business out of the state if the bill became law. "Such a mandate could force Remington to reconsider its commitment to the New York market altogether," said company spokesman Teddy Novin.
In California, legislation signed in 2007 by then-Gov. Arnold Schwarzenegger has been held up while the attorney general's office makes sure the technology is unencumbered by patents.
A gun rights group, the Calguns Foundation, went so far as to pay a $555 fee to extend a lapsing patent held by the developer to further delay the law's taking effect. "It was a lot cheaper to keep the patent in force than to litigate over the issues," foundation chairman Gene Hoffman said.
Todd Lizotte, an engineer who developed the technique in the 1990s, said he wants the patents to lapse, and the technology to be in the public domain.
Microstamping works much like an ink stamp. Lasers engrave a unique microscopic numeric code on the tip of a gun's firing pin and breach face. When the gun is fired, the pressure transfers the markings to the shell casings. By reading the code imprinted on casings found at a crime scene, police officers can identify the gun that was fired and track it to the purchaser.
Advocates of microstamping say it offers advantages over ballistic analysis, which has been used for more than a century and depends on matching incidental tool marks on bullets and cartridge casings to show that a particular weapon was used.
Under this system, when a cartridge casing is found to match one already entered in a computer database, such as the one maintained by the government's National Integrated Ballistic Information Network, a forensic examiner must confirm the match. And it is difficult to link the casings to a specific firearm unless the weapon is available.
Like other forensic methods, ballistic analysis has come under increasing scrutiny in recent years, and its reliability has been challenged in court. A 2008 National Academy of Sciences report said there was not yet conclusive evidence that the markings produced by a gun are identical over time and under different conditions.
But Lawrence Keane, senior vice president and general counsel for the National Shooting Sports Foundation, the gun industry's trade group, said microstamping was not reliable either. "There's no point in rolling out a technology that does not work," he said.
Mr. Keane and other opponents point to two early studies finding that the full numeric code could be read only about half the time on shell casings. In addition, they say, criminals could file off the numeric code or replace the firing pin. And the technology would not apply to revolvers, which do not discharge cartridge casings.
The NRA did not respond to a request for a comment on the microstamping issue. But on its website, it calls the method an "unproven technology," and says it "is easily circumvented by criminals."
The National Shooting Sports Foundation has estimated that implementing microstamping would increase the cost of a firearm by "well over $200," according to a fact sheet it issued. But advocates say the cost to manufacturers would be less than $12 a gun, the cap imposed by the New York Assembly bill.
In response to the critics, Mr. Lizotte said no new technology was tamper-proof, but that erasing the microscopic code was not easy. The technology is steadily evolving and becoming more reliable and cost-effective, he said, and waiting until it is foolproof makes no sense.
As for reading the numeric codes, Mr. Lizotte said a more recent study found that the full code could be read most of the time. Even when numbers are illegible, the code can be pieced together from other shell casings found at a scene or could be reconstructed much like missing license plate numbers.
The District of Columbia passed a microstamping law in 2009, but it, too, has yet to take effect. Bills introduced in at least four other states have made little headway.
In New York, Gov. Andrew M. Cuomo has said he supports microstamping legislation. "I'd like to see a microstamping bill passed," he said at an Albany news conferenceearlier this month. "I'm not optimistic that it will pass."
The trade group has worked steadily to block microstamping bills, spending $70,200 in lobbying expenses in New York in the first six months of 2010 to thwart an earlier version of the legislation, which was strongly backed by New York Mayor Michael R. Bloomberg. The NRA spent $80,219 lobbying against gun-control bills in the same period that year. The bill died in the state Senate.
Colin Weaver, deputy executive director of New Yorkers Against Gun Violence, said microstamping was needed because the difficulty of tracing firearms made crimes involving guns more difficult to solve than crimes that did not involve guns. An analysis by his organization found that from 2006 to 2009 in New York state, for example, 45.5 percent of aggravated assaults involving a firearm were solved, compared with 67.6 percent of aggravated assaults that did not involve guns.
Mr. Lizotte said microstamping had nothing to do with gun rights. "I'm a Second Amendment guy," he said, adding that he is an NRA member. "I just want to be part of the solution of protecting rights, because every time something bad happens with a firearm, my rights get curtailed."-->