A 22-year-old Houston woman whose partially clothed and battered body was found Sunday in a stream near a bike trail in Berwyn Heights had been strangled and sexually assaulted, Maryland National Capital Park Police said yesterday.

Park Police, who released the results of an autopsy by the Maryland medical examiner, said investigators also had recovered hair samples, latent fingerprints and other evidence from the crime scene and from the woman's car, which was in a lot near the park. Toxicological tests for the presence of semen are pending, Park Police Lt. Robert Hisamoto said.

The body of Margaret Perkins, a senior at Rice University who had come to the area three weeks ago for a summer internship at the Goddard Space Flight Center in Greenbelt, was found about 11 a.m. Sunday lying face down in a creek near the Indian Creek hiker-biker path, police said. Perkins's roommate contacted police about 11 p.m. Saturday when Perkins did not return from a run in the park near Berwyn Road and 55th Avenue.

Authorities estimated Perkins entered the park between 7:30 and 8:30 p.m. Saturday. She had left a note for her roommate saying that she expected to return home about 9 p.m., Hisamoto said.

Investigators believe Perkins was slain in a densely wooded area near the stream a few feet from the bike path and that her body was then pushed or rolled down the incline into the stream, Hisamoto said. Bloodstains and items of Perkins's clothing were found near the scene, Hisamoto said.

"The underbrush is so thick here that someone can be three feet into it and crouch down and you absolutely cannot see them from the bike path," Hisamoto said.

Perkins's green Mazda 323, parked in a Metro lot not normally used by visitors to the park, had been rifled, Hisamoto said.

The Metro parking lot is across the stream from the parking lot normally used by joggers, causing investigators to question whether the car was left there by Perkins or her assailant.

Hisamoto said yesterday that authorities do not know whether Perkins's death is related to that of a 24-year-old Arlington woman who was fatally stabbed near a bike path in Arlington.

Two other women also were attacked within an hour of each other on March 31 near the bike path in Rosslyn, the same night Ann Elizabeth Borghesani was stabbed to death. Borghesani's death was the first along a bike path in several years in the Washington area.

Hisamoto said that Perkins was the first person killed along the Indian Creek hiker-biker path in at least 20 years. The most recent sexual assault in the area, Hisamoto said, occurred in 1988 and resulted in an arrest.

Perkins's death is not believed to be related to the slayings of eight prostitutes whose bodies have been found in the last year in South Arlington and Alexandria.