In a recent Wall Street Journal op-ed piece, Harvard law professor Laurence Tribe urged the U.S. Supreme Court to uphold the District of Columbia's gun restrictions, the subject of a case the court will hear next Tuesday. Conceding that the Second Amendment guarantees an individual right to possess firearms, Tribe said that right does not rule out a decision to ban handguns while allowing "rifles, shotguns and other weapons less likely to augment urban violence."

The U.S. Court of Appeals for the D.C. Circuit disagreed, concluding that the district cannot constitutionally ban the type of gun most commonly used for self-defense. But even if Tribe is right that the Second Amendment allows the District of Columbia to ban handguns, he is wrong to assume District of Columbia residents are free to use long guns instead.

The District of Columbia requires that all firearms in the home, including rifles and shotguns, be kept "unloaded and disassembled or bound by a trigger lock or similar device." That "safe storage" requirement makes it pretty hard to use (SET ITAL) any (END ITAL) gun for self-defense, except maybe as a club. It makes the District of Columbia's gun laws look extreme even compared to those of other cities that ban handguns. If D.C.-style gun control does not violate the Second Amendment, it's hard to imagine what sort of gun control would.

The "safe storage" rule includes exceptions for guns kept in places of business and for guns "being used for lawful recreational purposes within the District of Columbia." It does not include an exception for self-defense at home.

Although three of the original plaintiffs in the D.C. gun-ban case said they wanted to keep functional long guns in their homes, the district did not claim they already were allowed to do so. Instead, it dismissed the very idea of armed self-defense as self-evidently absurd. "It cannot be seriously contended that the Second Amendment, even if applicable, guarantees private persons a right of ownership or possession of firearms on the basis of an asserted need to resort to self-help," the District of Columbia's lawyers told U.S. District Judge Emmet Sullivan.

But when the plaintiffs appealed Sullivan's dismissal of their complaint, the district suddenly began to suggest there might be exceptions to the "safe storage" requirement that are not mentioned in the statute. "The (D.C.) Council appears to have recognized that on rare occasions, in the event of a true emergency when necessary for self-defense, a gun could be unlocked," it said.

The only evidence the district cited for this claim was one council member's remark about how long it takes to unlock and load a gun. The district nevertheless suggested that "local courts are likely to give the law a narrowing construction for emergencies."

That possibility does not save the statute, the D.C. Circuit ruled, since "judicial lenity cannot make up for the unreasonable restriction of a constitutional right." Furthermore, a "narrowing construction" is by no means a foregone conclusion.

In its Supreme Court brief, the district asserts that an exception for self-defense at home "is fairly implied in the trigger lock requirement," but it does not explain how. Courts reasonably could read the law's specific "safe storage" exceptions to mean there are no other exceptions.

As Bellingham, Wash., attorney Jeffrey Teichert notes in a friend-of-the-court brief, D.C. courts have convicted residents of violating other gun regulations even when they used their weapons for self-defense. In one such case, the district argued that "self-defense would only excuse the use of the weapon, not the possession of the weapon."

This sort of uncertainty would be considered intolerable in the exercise of any other fundamental right. Could a law requiring that books in the home be kept under lock and key be redeemed by arguing that courts probably would give it a "narrowing construction"? If the right to keep and bear arms means anything in practical terms, it means that someone who uses a gun to defend himself in his own home should not have to throw himself on the mercy of the courts.