You Can Bring Gun to Capitol, but Not Through D.C.

It is also illegal to transport a firearm through the District if someone is traveling, for example, from Virginia to Maryland, Shelton said. "They should go around the District of Columbia," he said.

But not everyone shares the police lieutenant's take on the law.

Richard E. Gardiner, a former legislative counsel for the National Rifle Association who is representing Thompson, said his understanding is that a federal regulation that was passed in 1986 trumps D.C. law and allows guns to be transported through the District.

Webb and Thompson live in Virginia, where gun laws are much less strict.

Virginians who want to own guns need only pass criminal background checks, and only then if they purchase a firearm from a licensed dealer. Unlicensed dealers can sell firearms at gun shows in Virginia without conducting a criminal check. There is no requirement to register a gun in Virginia, but gunowners need a permit to carry a concealed weapon.

Thompson, who spent Monday night in jail, declined to comment when reached at his home in Stafford yesterday. He was given the day off but is expected back at work by tomorrow, Webb spokeswoman Jessica Smith said.

One version of events, provided by a Senate official, had Webb giving the gun to Thompson during a trip to the airport and asking him to keep the weapon while Webb was away. During a news conference Tuesday, however, Webb denied giving Thompson the gun.

If it turns out that Thompson was carrying the gun for Webb, that may pose a problem in the District, but it would probably not violate Virginia gun laws, legal experts said yesterday.

"I don't think there's anything wrong with that," said Arlington County Commonwealth's Attorney Richard E. Trodden. "Let's say I have a concealed weapon permit and I was going to the airport. I say 'Oh Lord, I have this gun here, let me put it in this satchel and I'm going to put it in the trunk, will you take it home for me?' He could do that. There wouldn't be any problem with that," Trodden said.

Staff writers Henri E. Cauvin, Timothy Dwyer, Tom Jackman and Nick Miroff contributed to this report.