Should people lose rights because they are sympathetic to, but do not actually help, terrorist groups? Should law enforcement and not judges be the arbiter of those sympathizers who should be placed on "watch lists"?

In Senate hearings on renewing the Patriot Act last week, Democratic Senators Ted Kennedy and Charles Schumer said the answer to both questions was "yes." Attorney General Alberto Gonzales and FBI Director Robert Mueller were grilled over a report showing that 35 gun purchases during the first half of last year were made by people on terrorist "watch lists," and the Senators called it a major public security risk.

Messrs. Kennedy and Schumer's proposed solution? Simply ban the sale of guns to people law enforcement places on the watch list.

The New York Times also sounded the alarm last week with an editorial entitled, "An Insecure Nation." The Times could not resist further sensationalizing the concerns. Fanning fears of terrorists being "free to buy an AK-47," it failed to mention that in the worst case these would be civilian, semi-automatic versions of the guns (just like any hunting rifle), not the machine guns used by militaries around the world.

The 35 "suspected" purchases, out of 3.1 million total transactions, were allowed because background checks found no prohibiting information. No felonies or disqualifying misdemeanors, for example. They were neither fugitives from justice nor illegal aliens. Nor had they ever disavowed their U.S. citizenship.

As Mr. Mueller pointed out, the FBI was alerted when these sales took place, but the transactions weren't stopped because the law didn't prohibit them. But Mr. Mueller assured the Senators that "we then will pursue [these leads]. We will not let it go."

Ironically, this debate occurred just weeks after the U.S. Supreme Court slapped down state laws that use police reports to set prison sentences because police reports are not reliable. Being on the "watch list" would also just rely on police reports. There would be no adjudication by a judge, no trial by jury, before being placed on the list. "Suspects" don't even have to be foreigners. They may have simply been individuals classified by law enforcement as sympathetic to militia groups or other undesirable domestic organizations.

Some politicians have recently experienced being on a "watch list" firsthand.

Interestingly, the same Senator Kennedy who wants to rely on "watch lists" was understandably upset last year and publicly complained to the Senate Judiciary committee when he was prevented from flying on an airplane because his name was placed on just such a "watch list." Rules did not allow him to be told at the airport why he was being denied a ticket, but fortunately for him being a U.S. senator meant the problem was eventually resolved with a few telephone calls.

Ultimately, though, despite all the fears generated, background checks simply aren't the solution. The federal Brady Act has been in effect for 11 years and state background checks even longer. But despite all the academic research that has been done, a recent National Academy of Sciences report could not find any evidence--not a single published academic study--that background checks reduce any type of violent crime.

Surely, it would be nice if these regulations worked. But it's hard to believe they will be any more successful stopping terrorists. Criminals and terrorists share much in common, starting with the fact that what they are doing is illegal. In addition, terrorists are probably smarter and engage in vastly more planning than your typical criminal, thus making the rules even less likely to be successful.

People need to remind themselves that a "watch list" is only that. It is not even probable cause. If you had probable cause that these suspects had done something illegal, you could arrest them.

Ironically, during the hearing, Mr. Kennedy spent most of his question time concerned that foreign combatants held in Guantanamo were not treated by the military with the respect that the FBI uses to handle American criminals. At the same time, he believes Americans can lose their rights to own a gun without an evidentiary hearing.

Democrats may think that people on "watch lists" should be denied their rights to own a gun, but what is next? Why not just make the system much "more efficient" and simply put all people on "watch lists" directly in prison?

John R. Lott Jr. is a resident scholar at AEI. Sonya D. Jones is a law student at Texas Tech University.