A 24-year-old Silver Spring woman was found strangled in her bed early yesterday morning, Montgomery County police reported. Hours later, a 23-year-old Northwest Washington man described as "a friend of the family" was arrested and charged with the woman's murder, police said.

The victim, Claire Levy, lived with her sister Vivian at 8039 Eastern Avenue, and worked as a computer programmer for the Nuclear Regulatory Commission, authorities said. Vivian Levy found the partly clothed body of her sister around 5 a.m. as she returned home from her work shift at a local restaurant, police said.

Police said there were no signs of forced entrance to the apartment, and no indication of how the woman was strangled.

Montgomery police spokesman Phillip Caswell said David Leander Stratmon Jr. of 7573 Alaska Ave. NW, was charged with the killing shortly after 4 p.m. Stratmon was being held without bond last night.

Neighbors described Claire and Vivian Levy yesterday as reticent, hardworking sisters. One neighbor said the two women were almost invisible neighbors who "smiled in passing but didn't believe in opening their door to someone they didn't know."

The two sisters have lived in the area more than three years since moving from Providence, R.I., where their father, Maurice, still lives, authorities said.

"You would see them on the way to the grocery store or on the sidewalk with an armload of books," said W. E. Kelsey, who lives downstairs. "They were friendly if you spoke to them, but sort of introverted. The only visitor I saw was an elderly man who seemed to be their father."

Kelsey said that late Saturday night he heard the sounds of a man and a woman quarreling outside the garden apartments. He heard car horns honk, he said, and then the noise died away. Kelsey said he was not sure if the woman he heard was Levy.