Alberto Isaac Navarrete Suarez, 33, a.k.a. Dario Gomez Lopez, or "Issac" was spotted in the Dallas area on September 4th, police said.
However, investigators say Suarez may have made it back to Mexico.
Investigators had previously said Suarez may have only been in Philadelphia for a short time. A Mexican driver's license was found at the crime scene with Suarez's alias.
It was about 9:30 p.m. on August 29th 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 showed 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.
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.
Anyone with information about Suarez is asked to call police at 215-686-TIPS.