It has been four months since the 7th Police District's Delta Unit launched Operation Zero Tolerance to cut down on the violence that left two teenage best friends dead, a third man injured and a baby grazed by a bullet in a bloody August weekend at 16th Street and Good Hope Road SE.

Despite the D.C. police effort, the problems have not been resolved. Young men still loiter near the curb on street corners peddling crack cocaine, and gunfire still occasionally pierces the night.

Lt. Lowell Duckett, commander of the Delta Unit, said his officers have made 80 arrests since the operation began Aug. 15. The unit has seized about 40 weapons, including the weapons believed to have been used in both killings.

Last week, an 18-year-old Southeast Washington man identified by police as Joel Caston was arrested and charged with murder in the Aug. 14 slaying of Rafiq Washington, 18.

Washington, who had drug charges pending against him at the time of his death, was cut down in a spray of gunfire about 10 p.m. in the parking lot of the New China Restaurant at 16th and Good Hope.

Caston, of the 1600 block of W Street SE, was arrested about 9:15 p.m. Wednesday at Alabama Avenue and Stanton Road SE by members of the Delta Unit. Duckett said Caston, who had been wanted since August on a murder warrant, was seen by Sgt. Donald Gossage and Detective Harry Hill traveling east in a vehicle on Suitland Parkway Wednesday night. Caston allegedly was holding a .45-caliber semiautomatic handgun to the head of a man whose identity was not released, Duckett said.

The two officers followed the car for more than a mile and asked for assistance from other members of the unit before moving in for the arrest. Caston was taken into custody without incident, Duckett said.

Duckett said Caston also is wanted in Prince George's County as a fugitive from justice on four charges of assault with intent to kill. Two of those charges were filed after he became a suspect in Washington's slaying, police said.

In early September, Delta Unit officers arrested a suspect, James Earl "Gizmo" Johnson, 20, in the Aug. 12 killing of Washington's best friend, Anthony Mardel Booze, 19.

Duckett urged residents of the area, which includes several small businesses, well-kept row houses and run-down apartments, to continue to work with police by turning in drug dealers and people who deal with guns.

"We're still not satisfied with the quality of life for the residents, because the area is still not free of the gang activity and drug-related offenses," Duckett said. "We're still looking for help from the community and religious leaders to get these kind of people off the street."

Anyone with information can call the Delta Unit hot line at 645-4360.