An Oakton man and woman were shot to death in their home Monday night, and their 19-year-old son was arrested and charged with their murders, Fairfax County police said.

Police accused Joshua Paul Cooke of killing his father, Paul C. Cooke, 52, and mother, Margaret Ruffin Cooke, 55. Joshua Cooke apparently called police about 7:30 p.m. Monday from the family's home in the 10500 block of Adel Road, about a half-mile west of Hunter Mill Road. Neighbors said the house's burglar alarm also sounded loudly and that an outside alert light was flashing.

Officers found Paul and Margaret Cooke shot to death in the basement of the house. A teenage daughter was away at college in Pennsylvania and was not involved.

Joshua Cooke was arrested at the scene. Police declined to discuss the circumstances of the shooting or whether Joshua Cooke was cooperating with investigators. He was being held without bond last night in the Fairfax County jail.

Paul Cooke is the son of Paul P. Cooke, the former president of D.C. Teachers College, now the University of the District of Columbia. The Cooke family declined to comment last night.

The Cookes were popular fixtures in the neighborhood, where they had lived since 1987, especially last weekend, when Paul Cooke was offering his snowblower to anyone who needed it. Neighbors said they saw the family earlier Monday as everyone dug out their driveways and they suspected no trouble whatsoever.

Joshua Cooke volunteered to help Philip Terzian and his family finish clearing their driveway on Monday. Then "Paul came over to offer his snowblower," Terzian said. "We talked about the storm. He was a very affable guy."

Terzian said the Cookes were "very protective" of their two children. "They took the trouble to send them to a religious school," Way of the Faith Christian Academy in Fairfax County, Terzian said, and "they kept them on a short leash. Josh is neat, pleasant, polite, looks you in the eye. He's very conscious of being dutiful to his parents."

Other neighbors also related tales of seeing the Cookes, especially in snowstorms, and said that their generosity was renowned. "Just a wonderful man," one neighbor said. "I'm as brokenhearted as I can be."

The occupations of Paul and Margaret Cooke were not available yesterday. Neighbors said Paul Cooke spent much of his free time gardening and maintaining the family's four-bedroom brick and clapboard rambler. Their driveway was completely free of snow yesterday, unlike any other in the neighborhood.

Police and ambulance equipment struggled to make their way along the hilly unplowed Oakton roads Monday night and had to summon a snowplow to get through. Police said the delay did not affect the Cookes, who were pronounced dead at the scene.

After high school, Joshua Cooke attended Virginia State University in Petersburg but dropped out after less than a year, neighbors said. He was hoping to enter the Marine Corps and was working at an area Jiffy Lube store in the meantime.