WASHINGTON - Two guns used in high-profile shootings this year at the Pentagon and a Las Vegas courthouse both came from the same unlikely place: the police and court system of Memphis.

Law enforcement officials told the Associated Press that both guns were once seized in criminal cases in Memphis. The officials described how the weapons made their separate ways from an evidence vault to gun dealers and to the shooters.

The use of guns that once were in police custody and were later involved in attacks on police officers highlights a little-known divide in gun policy in the United States: Many cities and states destroy guns gathered in criminal probes, but others sell or trade the weapons to get other guns or buy equipment such as bulletproof vests.

In fact, on the day of the Pentagon shooting, March 4, the Tennessee governor signed legislation revising state law on confiscated guns. Before, law enforcement agencies in the state had the option of destroying a gun. Under the new version, agencies can only destroy a gun if it is inoperable or unsafe.

Kentucky has a similar law, but it is unclear how many other states have laws specifically designed to promote the police sale or trade of confiscated weapons.

A nationwide review by the Associated Press in December found that over the previous two years, 24 states - mostly in the South and West, where gun-rights advocates are particularly strong - have passed 47 laws loosening gun restrictions. Gun-rights groups are making a greater effort to pass favorable legislation in state capitals.

John Timoney, who led the Philadelphia and Miami Police Departments and served as New York's No. 2 police official, said he did not believe police departments should be putting more guns into the market.

"I just think it's unseemly for police departments to be selling guns that later turn up," he said, recalling that he had once been offered the chance to sell guns to raise money for the police budget.

"Obviously, we always need the money, but I just said, 'No, we will take the loss and get rid of the guns,' " said the former police chief, who now works for Andrews International Inc., a security-consulting firm.

A Philadelphia police spokesman confirmed yesterday that the police force continues to destroy guns seized from criminals.

A spokeswoman for the Memphis police said gun swaps were a way to save taxpayers money.

One of the weapons in the Pentagon attack was seized by Memphis police in 2005 and later traded to a gun dealer; the gun used in the Jan. 4 courthouse shooting in Las Vegas was sold by a judge's order and the proceeds given to the Memphis-area sheriff's office. Neither weapon was sold by the Memphis law enforcement agencies directly to the men who later used them to shoot officers.

In both cases, the weapons first went to licensed gun dealers, but later came into the hands of men who were legally barred from possessing them: one a convicted felon; the other mentally ill.

The history of the two guns in the recent attacks was described by officials from multiple law enforcement agencies on condition of anonymity because they were not authorized to discuss details of the investigations. The Bureau of Alcohol, Tobacco, Firearms, and Explosives provided reports on the gun traces to the investigating agencies, but it is barred from publicly disclosing the results.

At the Pentagon, John Patrick Bedell carried two 9mm handguns, one of them a Ruger. Officials say Bedell, with a history of severe psychiatric problems, had been sent a letter by California authorities Jan. 10 telling him he was prohibited from buying a gun because of his mental history.

Nineteen days later, the officials say, Bedell bought the Ruger at a gun show in Las Vegas. Such a sale by a private individual does not require the kind of background check that would have stopped the purchase.

Mike Campbell, an ATF spokesman in Washington, would not confirm the details. He would say only that Bedell "appears to have purchased the gun from a private seller."

The gun already had changed hands among gun dealers in Georgia and Pennsylvania by the time Bedell bought it. Officer Karen Rudolph, a Memphis police spokeswoman, said her department traded the weapon to a dealer in 2008 for a gun that was better for police work.

The trail of the gun used at the Las Vegas federal courthouse is harder to pin down. Johnny Lee Wicks, 66, enraged over cuts to his Social Security benefits, opened fire with the shotgun at the security entrance to the courthouse. He killed one officer, Stanley Cooper, and wounded another. Wicks, like Bedell, was killed by officers' return fire.

Before that courthouse attack, what records exist suggest officers in Memphis confiscated that gun in 1998.

A judge in Memphis ordered the sale of the shotgun as part of a criminal case, and the proceeds of that sale went to the Shelby County Sheriff's Office, confirmed sheriff's spokesman Steve Shular. He said the gun dealer who bought it later sold the weapon to a dealer in Nevada. It is not clear how Wicks got the shotgun.

Rich Wyatt, a former police chief in Alma, Colo., who now operates a gun store - and who has bought weapons from police agencies - defended the practice of police selling guns.

"Maybe if they put the money they made selling the guns into training those officers better, they'd be better off," Wyatt said. "Nobody ever, ever questions selling a car that was used in a crime."