UPDATE: May 24, 10:47 a.m.
Police identified the offender as 29-year-old Adiren Mayo of Baltimore. He is charged with attempted murder, aggravated assault and related charges.

Original story follows:
PHILADELPHIA (KYW Newsradio) — A 30th Street Station employee has been hospitalized after a man stabbed him twice in the chest while inside a bathroom at the station, authorities said Monday.
Police say a suspect has been arrested and is expected to face charges including attempted murder and aggravated assault.
The stabbing happened at about 12:45 a.m. Monday morning.
According to preliminary information from police, the 41-year-old employee was trying to clean the bathroom, and he asked the man to leave and take his belongings.
Investigators said the man, 39, stabbed the victim twice with an unknown object, then fled the bathroom. The victim got to Amtrak Police for help. 16th District Police later arrested a suspect near 30th Street and Schuylkill Avenue.
Sources say the suspect is believed to be a homeless man from Maryland.
Police are still investigating the incident.
The crime comes a day after SEPTA Police said they were investigating a series of assaults and robberies by three women, while government leaders were attempting to find solutions for the recent rise in crime on the SEPTA system.