Alberto Isaac Navarrete Suarez, 33, a.k.a. Dario Gomez Lopez, or "Issac" was named as the suspect in a news conference Friday morning.
Dario Gomez Lopez is also the name found on a Mexican driver's license found in a pair of discarded pants at the crime scene.
"We know he was in the city for a short period of time, no more than a couple of months," Philadelphia Police Captain John Darby of Special Victims said.
Suarez is described as a Hispanic man, about 5'7" tall with dark hair and weighing about 140 pounds. His last known address is the 2600 block of 7th Street in Philadelphia.
It was about 9:30 Sunday night when a 22-year-old woman was standing on the northwest corner of 8th and Race waiting to catch a bus after getting off work.
Police say Suarez grabbed her by the throat and forced her into the Ridge Avenue Spur of the Broad Street subway which is across the street from Philadelphia Police Headquarters. That's where the woman was sexually assaulted.
The woman was nearly strangled during the attack, police said, however, a passerby called police and scared off Suarez.
Surveillance video was released on Monday showing the suspect, who was missing his pants, running from the scene. In one shot, the man is seen ducking under a mechanical gate of a parking lot.
Detectives are now processing forensic evidence to learn if he's responsible for other sexual assaults.
Police say its unclear if the suspect has fled the area which is why they have put out a widespread alert to local and federal agencies to be on the lookout for the man.
"This is a significant development that in fact we now know who perpetrated that crime and we're now asking for the public's help," Darby said. Anyone with information about the suspect is asked to call police at 215-686-TIPS.