The sniper who's gunned down innocent people around Washington, D.C., has used a high-powered rifle. Analysis of the bullets has proven that, and helped provide a link among the shootings.
Now the need is to use that technique to help connect the bullets back to a criminal.
But a bill requiring "ballistics fingerprinting" of firearms has been opposed by the National Rifle Association lock, stock, and barrel even though it might help tie a gun to criminals.
What gives a bullet an ID are the distinct etchings it receives as it flies down a particular gun barrel. The US Bureau of Alcohol, Tobacco, and Firearms calls those markings "unique," and has used this method to solve many crimes. Its database, however, derives solely from guns recovered from crime scenes.
A bill in Congress would require manufacturers to make a "fingerprint" of every gun they make and give this print to a national database. But the bill languishes because of the NRA's influence on lawmakers.
Opponents argue that the system won't cover guns already on the streets. Or that gun barrels can be replaced, thus changing the "markings." Or that criminals would simply use stolen guns. Yet even with those limitations, such a measure could catch more criminals and create a greater deterrent.
Maryland and New York are the only states with such databases, but these include only handguns, and only those bought in those states.
A national "ballistics fingerprinting" law won't solve every crime. But it's a tool law enforcement needs to solve crimes when other clues are few and far between.