A man sexually assaulted a woman in Chinatown across the street from police headquarters Sunday night before he fled the scene without his pants and brown work boots, police said.

He approached the 22-year-old victim as she waited for a SEPTA bus at 9:30 p.m. at 8th and Race streets, according to police. He grabbed her and forced her toward the secluded Broad-Ridge Spur subway entrance, where he raped and nearly strangled her.

"This victim could very well have sustained almost fatal injuries," said Capt. John Darby, of the police Special Victims Unit. "We want this guy off the streets. We want to locate this man."

The woman was treated and released from Thomas Jefferson University Hospital.

Police released surveillance video that shows what appears to be a Hispanic man fleeing the scene barefoot, in white fitted boxer-briefs and a black shirt with white sleeves, heading toward 10th and Spring streets.

In the slacks he left behind, police found a wallet containing $15 and a Mexican driver's license that provided the name Dario Gomez Lopez, 35, of Puebla, Mexico.

Darby said that they are working with various agencies, including the FBI and the Mexican Consulate, but have been unable to confirm the validity of the ID, adding that Lopez does not have a record.

Knowing that the pantless rapist is still at-large made many women in the Chinatown area quite uncomfortable.

"I'm going to have to watch out now for myself," said Star Qarkaxhia, 28, of Morgantown, who works in the area. She parks her car in the same lot that the man was seen running through after the attack.

"You would think it's a safe area," Qarkaxhia said. "We have cops here."

There was a SEPTA clerk at the station yesterday but his shift ended at 6 p.m., after which the station is without an agent. The station is closed on Sundays.

Cher Price, 40, said that she catches the train at that station everyday after work, but when there's no clerk, she walks down toward Market Street.

"Oh, my goodness, that does not make me comfortable," Price said. "That makes me very uneasy. This has happened before."

A SEPTA employee said that a woman was raped some time ago on the platform at the station.

"If they knew that happened before, do something about it," the employee said, adding that the parking lot has poor lighting.

The assailant is described as a Hispanic man, about 5 feet 7, 140 pounds, with black hair. Police are asking tipsters to call 215-686-TIPS.

To see the surveillance video, go to http://bit.ly/aoK8Wa.