Fairfax County police said they have identified a body found in a neighborhood park near W. T. Woodson High School as a 15-year-old student of the school, David Charles Gerhardt.

Gerhardt, of 9225 Nester Road, Fairfax County, was discovered Saturday lying in three feet of water with a single gunshot wound in the upper part of his body. He was found in the Woodson park section of Long Branch Park, near Whit- acre Road and Baccarat Drive just outside of Fairfax City, said police spokesman Warren Carmichael.

Police said they have not determined whether Gerhardt's death was a homicide or a suicide and are continuing their investigation of the shooting.

Charles L. Gerhardt, the youth's father, said his son was a student at Woodson High.

Carmichael said the youth, who had recently moved with his family to Nester Road from a nearby neighborhood, had run away from home on Feb. 18 and was staying with friends. Before his body was found, Gerhardt was last reported to have been seen on Thursday at Woodson High, police said.

One area resident said yesterday that parents in the neighborhood have been concerned about the safety of the park following an incident last year when some elementary school-aged children reported being harassed by a man in the park. Students from the high school and Olde Creek Elementary School often use the park as a shortcut to walk to school, residents say.

"It's nice to be there with your kids," said Bob Commisso, vice president of the Olde Creek Elementary School PTA. "But people tend to exercise some caution there. It's sort of like an automobile, you like to have one but it can be dangerous, too."

Paul Goree, president of the Somerset Olde Creek Civic Association, said he was "not aware of that park being a nuisance to anybody."