The technology exists to create a national ballistic fingerprint system that would enable law enforcement officials to trace bullets recovered from shootings, like those fired by the Washington-area sniper, to a suspect.
But because of opposition by the gun industry and the National Rifle Association, only two states have moved to set up such a system, and Congress has prohibited a national program, experts say.
"I definitely think that the technology is there, and it has been refined to the point where it is cost effective," said Joe Vince, a former chief of the crime guns analysis branch of the federal Bureau of Alcohol, Tobacco and Firearms.
"It would not be an imposition on the manufacturers or law enforcement or citizens, so I'm all for it," said Vince, who is now president of Crime Gun Solutions, a consulting company in Frederick, Md.
Now, the police can tell only whether bullet fragments or shell casings found at a crime scene match one another and come from the same gun. This information helps establish whether only one weapon was involved.
But without the gun itself, the police cannot go the next step and use this information to try to trace the shooter.
Even the technology that enables the firearms bureau to match bullet fragments or shell casings to one gun is new. A system was installed in 1999 after encouragement by the Bill Clinton administration, Vince and other experts said.
This system, known as the National Integrated Ballistics Information Network, optically scans the markings on bullets or shell casings, converting them into an electronic signature. This information is stored in a database and can be retrieved by computers in 235 police departments nationwide.
Gun control advocates and some law enforcement authorities like Vince have long advocated taking the next step, requiring gun manufacturers to keep an electronic record of the markings from bullets and shell casings when new guns are test fired. This data would be kept with the serial numbers of the guns.
With this information, the agency would be able to trace bullets and shell casings found at a shooting site to the gun maker and eventually to the buyer, said Vince and another former high ranking firearms bureau official.
But the National Rifle Association has opposed this, calling it tantamount to a national gun registry. The group succeeded in getting a provision in the 1968 federal Gun Control Act outlawing any national gun registry.
"This is just another example of NRA paranoia about gun registration, which prevents effective law enforcement," said Dennis Henigan, the legal director of the Brady Campaign Against Gun Violence.
Only Maryland and New York require gun makers to provide test-fired samples of bullets and shell casings when they sell a gun. Their programs have had limited effectiveness because they are new and because guns used in crimes could have been sold in so many other states.