A warmup jacket, left behind by a man who attacked a Fairfax County woman in her bed last month, led police to a Marshall High School student who has been charged in one of four assaults on women near a Metro station.

Michael S. Acosta, 18, a senior at Marshall, was charged with rape, two counts of forcible sodomy and abduction with intent to defile in the first attack, on Sept. 21. In that case, a 22-year-old woman walking home from the Dunn Loring-Merrifield Metro station about 10:15 p.m. was dragged into the woods at the edge of Stenholm Elementary School and assaulted.

Although Acosta is charged in only one of the Dunn Loring attacks, "we think he is responsible for all four," said officer Bud Walker, a police spokesman.

"We fully expect him to be charged in the others," Walker added, saying the initial charges allow Acosta to be held in jail while police and prosecutors compile other cases. Acosta was being held last night in the Fairfax jail.

Fairfax police began blanketing the neighborhood near Gallows Road, both north and south of the Metro station, after two women were raped and another fought off her attacker in late September and early October. Police said all the attacks took place in wooded areas near well-worn footpaths.

On Oct. 23, there was a fourth attack, this time inside a second-floor apartment on Manhattan Place, in the Westbriar Plaza apartment complex. Police believe the man entered through an unlocked deck door at 4:15 a.m. and jumped on top of a 26-year-old woman in her bed, according to a search warrant affidavit filed yesterday.

The intruder put his hands over the woman's mouth to try to quiet her screaming, then put a pillow over her face, sex crimes Detective Daniel R. Bibeault wrote in the affidavit. The intruder couldn't subdue the woman, and he fled.

The woman provided a description of her attacker that was very similar to the suspect in the first three incidents: A cleanshaven black man in his twenties, about 5 feet 7 inches, with short, black, straight hair.

And this time, the attacker left behind two pieces of evidence: a black, medium size Puma warmup jacket and a hockey puck with the logo of the Wichita Falls Rustlers junior hockey team.

Because two of the attacks occurred in the woods between the Westbriar Plaza apartments and the Merrifield at Dunn Loring Station apartments, Bibeault was there Wednesday night, watching the neighborhood.

Bibeault wrote that at 9:15 p.m. he encountered Acosta walking from the Merrifield apartments, where he lives, toward Manhattan Place. He interviewed Acosta briefly, noted that he was 5 feet 6 inches, clean shaven, and had short, black, straight hair.

Acosta is not black, but he has dark brown skin, and "at that time of night, the detective said he appeared to be black," Walker said.

On Thursday, Bibeault and another detective began investigating Acosta. According to his affidavit, Bibeault showed a photograph of the warmup jacket to one of Acosta's friends. The friend "identified it immediately as a jacket he had possessed up until one month ago," Bibeault wrote. "He said that he had let Michael Scott Acosta borrow the jacket and it has not yet been returned."

Acosta was arrested later Thursday night. Police then got a search warrant to take hair and saliva samples, finger and palm prints from Acosta so they could compare them against evidence left at the four crime scenes.

The second and third attacks occurred the night of Oct. 7. In the first, police said that a 45-year-old woman walking on a path between the Westbriar and Merrifield apartment complexes was grabbed and knocked down but that her attacker fled when she screamed.

Later that night, a 28-year-old woman in the same neighborhood was dragged into a secluded area and raped. Police were still on the scene investigating the first attack when the second occurred.

Fairfax school officials said Acosta enrolled at Marshall in September 2004. Marshall's acting principal, Jay W. Pearson, sent a letter to parents and guardians yesterday informing them of the arrest and noting that the crimes did not take place at school or involve any other Marshall students.

Staff reporter Maria Glod contributed to this report.