A 14-year-old Chantilly girl was found dead with sab wounds in the living room of her Fairfax County home yesterday afternoon, police said.

Officers said Nancy Anwyll, a teacher at Chantilly Secondary School, returned to her home at 13164 Morning Spring Lane to discover the parttially clad body of her daughter, Debbie Louise, sprawled on the floor.

The daughter, an eighth grade student at the school where her mother teaches world studies had returned home about an hour earlier by school bus, Police Cpl. Squire Brooks said.

Police said last night they had not found the weapon used in the stabbing and did not have either a motive or a suspect in the death.

Brooks said there was no sign of forced entry at the Anwyll home, which is located in the Greenbriar subdivision off Rte. 50 between Fairfax City and Dulles International Airport.

Police said an autopsy will be performed to determine the cause of Debbie's death.

Several Chantilly High School students who gathered outside the Anwyll home last night described Debbie as a good student.

Neighbors said the family had been living in the community about four years and that Debbie's brother Tom is a 10th grader at Chantilly High.

Debbie "was quiet and friendly," said John Collins, a car salesman who lives next door. He said that during the recent snow he had seen her and her mother shoveling their driveway.

"This is a quiet, middle-class neighborhood," said Collins. "You'd never think that something like this could happen here. When it strikes close to home you begin to wonder."

Several neighbors said they were taking extra precautions last night such as locking their doors and making sure their children were indoors.