A 17-year-old Bowie girl was found fatally shot yesterday on a paved path about two blocks from her home, Prince George's County police said.

The victim, identified as Stacey Seaton, was several weeks pregnant and had been shot in the back of the head, said a source who did not want to be identified because the case is under investigation.

Police said last night that they had not determined a motive.

"We are trying to canvass the area, find out . . . when she was last seen," said Cpl. Diane Richardson, a police spokeswoman. "Investigators are trying to develop a timeline" of Seaton's movements before her death.

A passerby walking in the 3200 block of Scarlet Oaks Terrace discovered the girl about 3:30 p.m. on a winding path in a wooded area behind a playground, Richardson said. Seaton was pronounced dead at a hospital a short time later.

"I'm surprised we had a murder occur behind a well-populated, well-traveled path during daylight hours," Richardson said. "This is a well-manicured, well-maintained area."

John Birckhead, principal of Bowie High School, said he knew Seaton when she was in ninth grade and he was a vice principal assigned as an administrator for her and several hundred other students.

"She was a nice kid," he said last night. "The contacts I had with her were very amicable. This has kind of taken us all by surprise."

He said he thought Seaton had transferred this year to Tall Oaks Vocational High School in Bowie. Larry McRae, the principal at Tall Oaks, said her name did not appear on a roster from earlier this year.

Neighbors in the quiet area around the Seaton home in the 13000 block of Silver Maple Court expressed concern about their safety as police cars filled the street and children and teenagers played.

"It makes me feel very uneasy," said a 33-year-old woman who declined to give her name out of concern for her safety. "Why this neighborhood?"

Kate Horspool, who lives next door to the Seatons, said she did not know the teenager well but said she was pleasant and would smile and wave in passing.

"They're a pretty quiet family," she said. "This is definitely pretty surprising."

Seaton was the 71st person killed in Prince George's County this year.

Staff writer Allan Lengel contributed to this report.