The bodies of two men and a woman were found yesterday lined up in a row, face down on a grassy slope of a park in the Langdon section of Northeast Washington, shot several times execution-style, D.C. police said.

Residents of the area of neat single-family houses said there had been some shots about 10 p.m. Monday, and then a long succession of shots about 1:30 a.m. yesterday. But the bodies weren't discovered until much later, at 10:15 a.m. yesterday, when passersby spotted them under a small stand of trees at the center of Langdon Park.

As many as eight homicide detectives worked on the case at a time yesterday. Last evening, police withheld the identities of the victims, and they did not describe the circumstances of the slayings or motive.

The killings in the park, which faces 18th Street just off Rhode Island Avenue NE, raised the number of homicides in the city so far this year to 142. There had been 144 slayings in the District at this time last year. There was another homicide in the same neighborhood 11 days earlier.

As uniformed officers and detectives canvassed the area yesterday, residents gathered on either side of the four-block-long park and spoke of how crime has worsened their neighborhood.

"It's very typical to hear shots" at night, said Jo Tingle, who lives at the end of the alley along the park's north side. Tingle, who said she had moved to the neighborhood four years ago, said she felt "relatively safe" until last year.

But now, she said, the alley has become a common place for prostitutes from Rhode Island Avenue to take their customers. "I find condoms in the alley all the time," she said. "I find them in the park too, which is really a drag because I sometimes take my kids down there."

She and others who watched police from the alley, said that the park also has become a hangout for people drinking and taking drugs.

Another woman, who asked not to be named, stood at the edge of the park and watched as detectives worked around the three bodies. "I've lived here {in the neighborhood} all my life," she said. "You used to be able to ride your bike all over . . . . Now, I go to work, go to the grocery store, go to church. What else can you do?"

Tingle said she wished squad cars would patrol the park by driving along the walkway that runs through the center of it, "just to make their presence known."

Onlookers said someone called police about the shots fired early yesterday and that a squad car came to the alley and scanned the park with its lights, but appar-ently officers didn't see anything untoward.

Wayne Hudgens, who said he lives a few blocks away, also said the area needs more foot patrols. "They need to spread them {police} out and make them walk," he said.

Hudgens recalled the Langdon area's last killing. He said that on the morning of April 13, he heard shots as he was getting dressed for work. Later, driving down Rhode Island, he saw police officers stringing up yellow tape at an adjacent alley. Police said Paul E. Watts, 20, of the 1300 block of Childress Street NE, had been shot to death in an alley near Evarts Street NE in an apparent shootout.

Hudgens said that unless foot patrols were beefed up in the area, "you'll see a lot more ribbons before the summer's over."

Yesterday's killings were the first multiple execution-style slayings in the District since two men were bound with handcuffs, their heads wrapped in duct tape and shot in Northwest Washington last October.