A 26-year-old Navy enlisted man was arrested by Takoma Park police last night and charged in the slaying of a couple found shot to death in bed in their apartment on Tuesday.

Police Chief Tony Fisher said the suspect, David W. Stigger, a petty officer second-class, apparently had been friends with the slain couple, Lorenzo Vener, 25, and his wife, Diorvette, 24, and had been seen at their apartment frequently in recent weeks.

Both Stigger and Lorenzo Vener, also a Navy petty officer, worked at the Naval Security Station in the District, where Vener was a disbursing clerk, police said.

The Veners apparently had given Stigger a key to their apartment in the Park Ritchie building on Maple Avenue in Takoma Park, police said.

Stigger, who was arrested at his home in the 6500 block of Hillman Drive, Forestville, was charged with two counts of first-degree murder and two of using a handgun in commission of a felony and burglary.

Two police officers who had knocked on the door of the Veners' apartment early Tuesday in response to a complaint of the sound of gunfire were greeted by a man who opened the door and told them everything was all right. The officers left, and when they returned to investigate further, they found the Veners' bodies. The couple's 4-year-old daughter, Jahmilka, was unharmed and asleep in an adjacent bedroom.

The man who answered the officers' initial knock at the apartment is believed to be Stigger, police said last night. They said the arrest was made after the officers picked him out of a large group photograph of workers at the Naval Security Station.

Police said they believed that Stigger let himself into the Veners' apartment with the key he had. They said the motivation for the slayings was still under investigation.

Spent cartridges were found in the apartment, and police said that a box of matching bullets was found last night when officers executed a search warrant at Stigger's home. The cartridges and bullets were believed to be compatible with a .38 Colt semiautomatic handgun that Stigger registered in Maryland two years ago, police said.

Earlier yesterday, Police Chief Fisher said the officers who knocked at the Veners' apartment about 3:40 a.m. Tuesday "gave a citizen the benefit of the doubt" when they left the apartment after encountering the "calm and intelligent" man who answered the door.

"There was nothing suspicious about his actions," Fisher said. "He told the officers everything was all right. There were no problems."

The officers sensed something was wrong after going to a nearby police station and talking with a dispatcher.

"It was an intuitive thing," said Fisher. "This gut feeling. I'm not sure you can explain it, but it moved the officers to return" to the 18-story apartment building.

Minutes later, police found the Veners' bodies.

Yesterday, the police department's entire six-member detective squad was assigned to the case, the first killings this year in the small municipality.

As a disbursing clerk at the Naval Security Station in the District, Vener was responsible for a $2 million monthly payroll. Diorvette Vener was the head teller at a Citibank branch in Northwest Washington.

Fisher said his officers reacted responsibly by not demanding entry into the apartment because only one person in the 189-apartment complex had complained of hearing a gunshot and because there were no signs of violence.

"We didn't receive two or three calls from people across the hall or on another floor," Fisher said. "If the call had reflected a domestic problem, we would have responded in another way."

Staff writer Ruben Castaneda contributed to this report.