Police are looking for the man who assaulted a 23-year-old man for his cell phone on the Market-Frankford Line on Oct. 30.
The attack occurred about 8:30 a.m. as the train, heading toward the 69th Street terminal, approached the Berks station, police said.
In surveillance video of the incident, the attacker is seen standing in the doorway opposite the victim and watching him play with his smartphone. After the victim takes a seat, the attacker lunges forward and repeatedly punches the man in the face and demands the phone.
Passengers rushed to help the victim, but the attacker jumped out at Berks station before he could be detained. The victim was not seriously injured.
Police described the attacker as a 5-foot-11, dark-skinned man with a beard and slim build.
Submit a tip via telephone at 215-686-TIPS (8477), or text a tip to PPD TIP (773847).