PHILADELPHIA — Police who traced a rape suspect's trail from Philadelphia to Texas to Mexico say they have him in custody after a four-year pursuit.

They also consider him a suspect in the rape of a teenager in Pittsburgh a few months before the Philadelphia woman was grabbed off the street in August 2010.

Alberto Suarez, 37, left behind his pants, wallet and a digital camera when passers-by came upon the scene where a woman was being attacked less than a block from Philadelphia police headquarters. The 22-year-old woman was nearly unconscious from the savage nighttime attack, police said.

The wallet contained the false name Suarez had used to enter the United States, but the photographs quickly led police to a house in South Philadelphia and contacts with whom he worked as a day laborer.

They followed his trail from Pittsburgh to West Virginia to Texas, where he slipped into his native Mexico. However, Philadelphia detectives, with help from the FBI, had Suarez detained in Mexico City in 2012 and, after arduous legal proceedings, extradited to Philadelphia late Monday.

"While it seems like a long time ... in Mexico, the judicial process works much, much slower, especially when he's a (Mexican) national," FBI Special Agent in Charge Edward J. Hanko said at a news conference Tuesday.

DNA collected at the scene was run through a national database and appears to match a sample from a March 2010 rape in Pittsburgh, according to Lt. Anthony McFadden of the Philadelphia special victims unit.

Suarez was expected to be charged Tuesday with rape, attempted murder and aggravated assault in the Philadelphia case. Charges in Pittsburgh could follow. He does not yet have a lawyer.

For the Philadelphia victim, the arrest was "bittersweet," McFadden said.

"She had four years of trying to get some closure, some relief," he said.

The arrest has reopened those wounds, while ending the risk that the rapist would harm anyone else, the detective said.