The list of metropolitan area neighborhoods besieged by drug-related violence has grown to include Glenarden, a once-quiet Prince George's County community where a police officer shot and killed a drug suspect yesterday.

The shooting was the latest in a series of violent incidents at the deteriorating Glenarden Apartments across Brightseat Road from the Landover Mall. In the last six months, police said, seven homicides have been reported in the apartments.

Yesterday's shooting, the first by a police officer, was the most recent example of how drugs and violence have transformed once peaceful residential communities into battlegrounds, among them Hanover Place, Paradise Manor and portions of Condon Terrace in the District and the Charles Houston Recreation Center area in Alexandria.

Since early this year, police have made 420 arrests in the 592-unit Glenarden Apartments, a complex that authorities say has become a major marketplace in the drug trade. A seven-member police unit has been assigned to the 50-building complex to attack drug trafficking.

Police said the shooting early yesterday morning resulted when an officer on patrol spotted a man he suspected of being a drug dealer.

According to police, Anthony Jerome Thomas, 27, was shot in the chest by Officer Theodore Mathis, 25, a three-year member of the force, after he chased Thomas into an apartment.

The violence has accelerated in the past half year, a development that Glenarden Mayor James C. Fletcher Jr. said "is just progression. It's been coming to a head."

Last month, Glenarden residents packed the town's community center to complain to county officials and police about the violence that has engulfed the apartment complex but not yet spilled over heavily into nearby neighborhoods of $75,000 to $150,000 single-family houses.

"It's been going on for two years, and we've just gotten sick and tired of it," said state Sen. Decatur W. Trotter (D-Prince George's), who represents the area.

"Our neighbors complained of vans with New York or Florida tags," Fletcher said, referring to an obvious influx of outsiders.

Police said the area has become widely known as a drug supermarket and attracts buyers from Northern Virginia, the District, and Howard, Montgomery, Charles and Anne Arundel counties.

The incoming traffic has prompted some Glenarden residents to begin recording the license plates of automobiles as they enter the complex and others that park in front for an extended time.

But police are at a loss to explain why the area is experiencing an increase of violence greater than other parts of the county.

"I don't know. It could be the demographics or the easy access to the Beltway. I just don't know why," said Cpl. Bruce Gentile, a police spokesman, who could not provide precise statistics to compare crime rates with other areas of Prince George's.

Mathis gave police investigators this account of yesterday's shooting: He was on a routine patrol when he saw three men making what appeared to be a drug transaction. One of the men ran away, and Mathis questioned the other two but did not make an arrest.

A short time later, about 1:45 a.m., the officer saw an individual he believed to be the man who had fled. As Mathis approached, the man ran into a second-story apartment at 3034 Brightseat Rd., tossing aside packets as he ran. Mathis told police the man entered an apartment occupied by an unidentified woman. As Thomas entered the apartment, the woman began screaming, "Get out of here," alerting Mathis, who blocked the door with his foot.

Mathis said he told Thomas several times to open the door and to raise both hands. Thomas opened the door but, police said, had one hand in his jacket pocket. Mathis thought he was reaching for a weapon and fired one shot from his service revolver, hitting Thomas in the chest. Thomas was taken to Prince George's Hospital Center, where he died an hour later. No weapon was found, police said.

For nearly a year, a special unit of county police has been stepping up patrols in the apartment complex, handing out trespass notices and warning visitors of the potential for violence. Sgt. John Moss, who heads the task force, said that about 23 percent of the apartments are vacant or occupied by someone other than the leaseholders.

In some cases, tenants have have moved out, leaving the apartments open to drug dealers who use the space for storage, Moss said. Many more apartments, he said, operate as "crack houses," where drug users can elude police by slipping into the apartment to smoke or inject drugs.

Police suspect that while not all of the apartment dwellers are involved in the drug trade, many help suspects elude police by opening their doors when police chase them into a building.

Fletcher and police also blame landlords who they said have little to do with the day-to-day apartment operations. However, Housing Resources Management Inc., the property manager, has cooperated with police. On Tuesday evening, a few hours before the shooting, property administrator Lydia Garcia sat in the front of a police cruiser, signing trespass warning notices that were passed out to people stopped by Moss' unit.

"We know that there's a whole lot of drugs here; we wouldn't be here if there wasn't," Cpl. William Brooks said Tuesday as he and his partner cruised the apartment parking lot.

Moss said that police efforts will increase, with the impounding of cars used in drug deals and a promise from prosecutors not to accept plea bargains.