A Richmond man, stepping off a bus at the Greyhound Bus Station near the Capitol, was arrested Thursday for bringing three semiautomatic weapons into the District, a spokesman for the Bureau of Alcohol, Tobacco and Firearms said yesterday.

Michael Anthony Eberhardt, 31, allegedly purchased 72 guns in Virginia during the past 18 months and brought them into the District to sell, said spokesman Dick Pedersen. Many of the weapons were the semiautomatic Tec-9s favored by local drug dealers.

Eberhardt's arrest follows an investigation by the Bureau of Alcohol, Tobacco and Firearms into six drug-related crimes involving handguns in Washington, Baltimore and New York, Pedersen said.

Yesterday Eberhardt was charged in D.C. Superior Court with three counts of carrying a pistol without a license and three counts each of possession of unlicensed firearms and unlicensed ammunition, according to a spokesman for the U.S. attorney's office. Eberhardt also is charged with a probation violation, the spokesman said.

When he was arrested, Eberhardt had three firearms with him including a Tec-9 and two Davis .32-caliber, chrome-plated, semiautomatic guns, said Pedersen.

Semiautomatic handguns have clips instead of cylinders, are more easily concealed because they are flatter, and can be fired and reloaded more quickly than a revolver.

Eberhardt routinely took the guns into the Columbia Heights neighborhood in Northwest Washington where he sold them, Pedersen said.

He said it was legal for Eberhardt to buy the guns in Virginia because he is a resident but it is illegal to transport the guns into the District because of the city's tough gun control laws.

Michael J. Bregman, special agent in charge of the Washington district office of the Bureau of Alcohol, Tobacco and Firearms, called Eberhardt a "major trafficker in firearms."

"We believe there is a conspiracy to bring guns into the District and we hope to have other arrests in this case," he said. "Everyone wonders where all the guns are coming from. This is certainly part of the answer."

Federal agents became aware of Eberhardt's gun purchases after the agency was contacted several times by various law enforcement officers who asked the Bureau of Alcohol, Tobacco and Firearms to track the owner of guns they had seized. Eberhardt used his name to make the purchases in Richmond.

Pedersen said the agency does not keep a file on all guns manufactured or sold in the country and that the agency traces ownership on guns only when asked to by law enforcement officers.

The agency tracks the handgun from the manufacturer to the wholesaler, and from the store owner and to the purchaser, said Pedersen.

An agent observed Eberhardt purchase three guns in Richmond on Thursday and then board a bus heading for Washington. The agent had just enough time to scramble aboard the bus before it pulled out, Pedersen said. He stayed on the bus until Eberhardt got off in Washington.

"We were aware of this guy for several months but we had a hard time tracking him because we didn't know how he was traveling between Richmond and Washington," Pedersen said.

Last month the agency arrested a District man who they said used false identification to purchase more than two dozen semiautomatic guns in Woodbridge and then bring them into the city where he sold them to drug dealers. David Isom, 30, of the 600 block of Irving Street NW was arrested on Dec. 23 and arraigned in U.S. Magistrate's Court in Alexandria on one count of purchasing a handgun with a false identification.

On Jan. 21, Isom was released into the custody of a third party. The next day he was arrested in Baltimore on a probation violation and is being held pending trial, said a spokesman for the magistrate's courts.