Adam Winkler
Adam Winkler

Adam Winkler is a professor in the UCLA School of Law and an expert on constitutional law and gun control. He is the author of “Gunfight: The Battle over the Right to Bear Arms in America.” This op-ed appeared in the New York Times.

The massacre in Florida is a horrifying reminder that terrorists don’t need airplanes to kill scores of people: All they need are commonplace firearms. Gun-control groups are already issuing calls to do more to keep suspected terrorists from buying guns, while those against stricter gun laws say we shouldn’t deny people their constitutional rights on the basis of mere suspicion. They are both correct. But there is a solution.

Federal law bars felons, the mentally ill, drug addicts and people convicted of domestic violence misdemeanors from possessing firearms. Nothing, however, prevents a suspected terrorist from walking into a gun store and buying as many guns as he wants. According to a report by the F.B.I., more than 200 people on the terrorist watch list legally bought guns from federally licensed dealers in 2010.

Islamic terrorists seem to be well aware of this loophole, and some have urged their followers in America to take advantage of our lax gun laws. In a 2011 video, a spokesman for Al Qaeda noted the easy availability of weapons in the United States and asked sympathizers, “So what are you waiting for?”

Since the Sept. 11 attacks, the government has kept suspected terrorists from boarding airplanes by placing them on no-fly lists. Isn’t it time we also had no-buy lists? In a speech on Monday, Hillary Clinton, the presumptive Democratic presidential nominee, seemed to support this idea, saying, “If you’re too dangerous to get on a plane, you are too dangerous to buy a gun in America.”

Although endorsed by both the Obama and George W. Bush administrations, the creation of something like a no-buy list has been vigorously opposed by the National Rifle Association. The gun lobby objects that the administrations’ proposals would give the attorney general too much discretion over who is put on such a list. No one should be deprived of constitutional rights on the shaky ground that the attorney general merely suspects the person might be a terrorist.

We should take the N.R.A.’s criticisms seriously. Due process of law is a vital constitutional principle and Americans have a right to own firearms for self-protection.

Does this mean we should drop the idea of a no-buy list? No. It just means we need one that is fair.

One promising model can be found in Fourth Amendment law on search and seizure. The Constitution allows the government to invade our privacy by, say, wiretapping our telephones, for law enforcement purposes in limited circumstances. First, the prosecutor must have probable cause, or sufficient evidence of wrongdoing. Second, the search must be approved by the courts.

Such principles, which were part of the framers’ broad conception of due process, have not always been followed when it comes to national security, from the internment of Japanese-Americans during World War II to the Bush administration’s warrantless surveillance program. Yet those principles can provide a sound basis for no-buy lists.

Congress should authorize no-buy lists but mandate that appropriate protections be put in place. If the attorney general believes a suspected terrorist should be added to the list, she should have to go to court first and offer up evidence. Only after concluding that the attorney general has probable cause should the court approve the denial of the suspect’s right to buy a gun.

This court proceeding, of course, would be secret. Although that denies the person included on the no-buy list the opportunity to rebut the attorney general’s evidence, we do the same thing every day with search warrants and wiretaps for criminal suspects. Our right to bear arms is no more fundamental than our right to privacy, and treating them similarly can help keep us safer from terrorists.

For maximum secrecy, Congress could assign these probable cause determinations to the jurisdiction of the existing Foreign Intelligence Surveillance Court. The judges on this court have a deep understanding of the nation’s national security threats.

Similar procedures for denying someone the right to possess firearms are already in place for domestic abusers. A person harmed or threatened by her spouse can obtain a court injunction barring the spouse from being near her. Under federal law in certain cases, the spouse will also be denied the right to have a gun.

Some opponents of gun control complain because such injunctions are issued without first notifying the spouse, but the courts have consistently said the practice is constitutional.

To ensure that the no-buy list isn’t being abused, the law should also require that the attorney general file periodic, confidential reports to an appropriate congressional oversight committee where pro-gun lawmakers can police any executive branch abuses.

Of course, like any law, a no-buy list won’t be a perfect solution. (And an imperfect version of a no-buy list, with tight deadline requirements, was proposed in the Senate last year.) With over 300 million guns in America and private gun sales allowed with no background check whatsoever, a determined terrorist will most likely still be able to obtain guns. Yet the easiest, most convenient way to buy guns — from a gun store, with the best prices and selection, like the one where the Orlando attacker bought his guns — wouldn’t be available.

The best way to honor those who died in Orlando is to do everything we can to reduce the chances of more innocent lives being lost to terrorism. And we can do it while respecting the Constitution.