A man killed in an ambush-type slaying in an apartment building in the Columbia Heights section of Northwest Washington Monday night was identified yesterday as Vicente Gudiel Lopez, 38, of the 3000 block of 16th Street NW, police said.

The shooting just before midnight -- one of five killings from Saturday to Monday -- roused residents in the building in the 1300 block of Park Road NW. Two tenants said they looked out their doors and saw the victim lying in the hall, near the stairs leading to the front door.

Police said Gudiel was apparently leaving a first-floor apartment when he was shot. Three cartridge cases were found just outside the three-story brick building.

"It just seemed like an ambush . . . . They were waiting for him," said police Capt. James Coffey. "When he opened the door, they shot him."

It was the 67th homicide this year.

About two hours earlier, and just two blocks away, police found another man shot in the arm and the chest on the corner of Park Road and 11th Street NW. He had been talking at a public telephone about 10:15 p.m. when two men aproached him, fired several times and fled in a light blue Ford Escort, Coffey said.

The victim, whose name was withheld, was taken to Washington Hospital Center and was reported in serious but stable condition. Coffey said detectives were trying to determine whether the two incidents were related.

Earlier Monday, just after noon, police found a 20-year-old man in an alley behind the 1900 block of Maryland Avenue NE. The victim, identified as Andre Weaver, of the 1700 block of Benning Road NE, was suffering from multiple gunshot wounds. He was later pronounced dead at D.C. General Hospital.

There were three other unrelated homicides over the weekend, and detectives arrested three people in connection with two of the killings. James N. Hall, of the 1400 block of New Jersey Avenue NW, was arrested and charged with the second-degree murder in the shooting death of Guy P. Washington, 22.

Washington, of the 200 block of Adams Street NE, was found lying in a stairwell at 4:45 a.m. Saturday suffering from several gunshot wounds. He later died at Washington Hospital Center. Police said the motive is still under investigation.

Maurice Fields, 20, and Darrell Williamson, 18, were arrested in the slaying of Kenneth May, 38. May, of the 1100 block of Sursum Corda Court NW, was found shot about 8 p.m. Sunday in a parking lot on the 300 block of Riggs Road NE.

Fields, of the 2100 block of Third Street NE, and Williamson, of the unit block of Florida Avenue NW, were charged with first-degree murder. Police did not reveal a motive.

Police also are still looking for suspects in the killing of Earl M. Waters, 31, who died of gunshot wounds Saturday afternoon at Howard University Hospital. Waters, of the 2500 block of 13th Street NW, had been taken to the hospital by a private vehicle, police said.

Homicide investigators later learned that Waters had been shot while on the 1000 block of Euclid Avenue NW, police said. There are no suspects, and the motive is under investigation.

Staff writer Debbi Wilgoren contributed to this report.