Sunday, February 06, 2005


Ballistic fingerprinting was all the rage just a couple of years ago. Maryland and New York were leading the way where a computer database would record the markings made on the bullets from all new guns. The days of criminals using guns were numbered. Yet, a recent report by the Maryland State Police's forensic-sciences division shows that the systems in both states have been expensive failures. New York is spending $4 million per year. Maryland has spent a total of $2.6 million, about $60 per gun sold. But in the over four years that the systems have been in effect neither has solved a single crime. To put it bluntly, the program "does not aid in the mission statement of the Department of State Police."

The systems have drained so many resources from other police activities that ballistic fingerprinting could end up actually increasing crime. In New York, how many crimes could 50 additional police officers help solve? ....

Precisely because friction causes wear, a gun's ballistic fingerprint changes over time � making it drastically different from such forensic evidence as human fingerprints or DNA. The recording of a child's fingerprints or DNA still allows for identification much later in life; the same is not true of the bullet markings. A ballistic fingerprint is less like a human fingerprint than it is like the tread on a car tire.

Brand-new tires are essentially identical, so new-tire tracks at crime scenes leave investigators with pretty limited information. Unless there happens to be a particular imperfection, only the brand and model of the tire can be identified. Imprints on bullets are similar. When a bullet is fired from a new gun, investigators can typically identify only the type of ammunition and the type of gun. Over time, though, friction causes the tread on tires to wear. It would be easy to take the tire tracks left at a crime scene and match them with a suspected criminal's car; but the more the car is driven after the crime, the harder it is to match the tire tracks left at the scene to the tires when they are eventually found. Similarly, the greatest friction on a gun occurs when the gun is first fired � and that dramatically reduces the usefulness of recording the gun's ballistic fingerprint when it is purchased.

Moreover, ballistic fingerprinting can be thwarted by replacing the gun's barrel � just as criminals can foil tire matching by simply replacing their tires. In general, the markings on bullets can be altered even more quickly and easily than the tread marks on tires: Scratching part of the inside of a barrel with a nail file would alter the bullet's path down the barrel and thus change the markings. So would putting toothpaste on a bullet before firing it.....

While registering guns by their ballistic fingerprints is a relatively new concept, we have had plenty of experience using gun registration in general, and it has come up woefully short. A few years ago, I testified before the Hawaii state legislature on a bill to change registration requirements. Hawaii has had both registration and licensing of guns for several decades.

In theory, if a gun is left at the crime scene, licensing and registration will allow the gun to be traced back to its owner. Police have probably spent hundreds of thousands of man-hours administering these laws in Hawaii. But despite this massive effort, there has not been a single case in which police claimed that licensing and registration have been instrumental in identifying a criminal.

From John Lott

Utah: Bill to "allow" loaded guns in cars: "Gun owners -- even those without a concealed weapons permit -- would be allowed to carry their loaded weapons in cars under a bill being prepared for the Utah Senate. Sen. Mark Madsen, R-Lehi, said he is drafting a bill, SB175, that would give gun owners the same access to weapons in their cars that they have in their homes. 'It's called the 'home-castle' principle,' Madsen said. 'If you're in your car, the same right you have in your home extends to your car. It's pretty simple.'"

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