Philip Cook and Jens Ludwig: Gun Control Lessons

If a national firearms database had been available to authorities investigating the sniper case, it's a good bet that the terror would have ended sooner and lives would have been saved.

The big break in the investigation came from the ability to match a fingerprint left at a robbery-murder scene in Montgomery, Ala., with fingerprints collected over the years by the Immigration and Naturalization Service. The suspects' vehicle also was identified because vehicles (unlike guns) must be registered, and registrations are available for investigators to search. Without fingerprinting and vehicle registration, the suspects might still be at large.

But one important resource was missing from this effort: data on guns.

Each gun leaves its own unique "fingerprint" on every round it fires in the form of marks on the back and side of the shell casing and on the sides of the bullet. Investigators in the sniper attacks found cartridge cases in at least two of the shootings, and bullet fragments were taken from the victims. These were helpful in determining that the same gun had been used in each case and in establishing that the Bushmaster XM15 .223 caliber rifle found in the arrestees' automobile was the murder weapon.

The equipment for analyzing the marks on cartridge cases and bullets is widely available '" the U.S. Bureau of Alcohol, Tobacco and Firearms is now equipping 223 agencies and networking them so law enforcement agencies can search for links in different crimes of gun violence. But in paying for this program, Congress limited ATF to storing ballistics data on guns used in crimes.

The logical next step would be to require that all new guns be test-fired before leaving the factory with the resulting "fingerprint" stored in a database for future reference by law enforcement. If that requirement had been in place in June when the Bushmaster factory shipped the weapon used in the sniper spree, investigators would have been able to match the marks on the crime-scene cartridge cases and identify the make, model and serial number of the snipers' gun They could have traced it to the retail dealer '" as was actually done after the gun was found. If that dealer had kept the sales record as required by federal law, it would have provided investigators with a name, address and other information. And even if the dealer had failed to keep the record (as appears to be the case), the investigators still would have acquired some important leads.

There is a variety of ways to design a ballistics fingerprinting system. Maryland and New York have implemented such systems last year, and we'll learn a lot from them over the next few years. Any feasible system would be limited in scope and less than perfectly accurate, but the same can be said of all other investigatory aids as well, such as fingerprinting and DNA evidence. Paul B. Ebert, commonwealth's attorney in Prince William County, Md., said, "To match a bullet to a crime scene is sometimes the only way to connect a suspect to a case, short of having credible eyewitnesses."

Opponents fear the introduction of a ballistics database. Some see it as a big step toward gun registration, which in their view is simply a prelude to government confiscation. But to us, the abuse of a comprehensive ballistics database seems highly unlikely, and it surely is no more of a threat to personal freedoms than a variety of existing databases. The D.C.-area sniper attacks remind us that preserving the anonymity of gun owners comes at some cost to the rest of the public's safety.

Philip J. Cook is on the faculty of the Sanford Institute of Public Policy at Duke University. Jens Ludwig is on the faculty of the Georgetown Institute of Public Policy. They are co-authors of "Gun Violence: The Real Costs."