Montgomery County police are searching for a gunman who walked into the living room of a Silver Spring home Saturday night and killed a 24-year-old man and his girlfriend.

Police said Earnest Randolph Williams, 24, and Erica Campbell, also in her twenties, were dead on the living room floor when they arrived at the house in the 8400 block of Tahona Drive. Although police did not release the victims' addresses yesterday, a neighbor said Mr. Williams lived at the home with his parents.

The shooting occurred about 10:30 p.m. An unidentified man who was in a bedroom watching television at the time of the shootings told police he ran into the living room when he heard screams and the gunshots. After discovering the victims on the floor, he ran from the house and called police.

Investigators did not disclose the number of shots fired or the location of the wounds. The bodies were taken to the state medical examiner for autopsies. A motive has not been determined, police said.

"There are several possible motives," said Detective Ed Day. "We have not closed any avenues."

He said no suspects have been identified.

Ms. Campbell's two daughters, ages 6 and 3, were in the house at the time of the shooting, but were not injured. The older girl was asleep on a couch when police arrived.

The children are in the custody of Child Protective Services.