Authorities released surveillance video of the man on Thursday morning.
The shooting occurred around 12:19 a.m. Wednesday on the 5200 block of Market Street.
Police received numerous calls for gunshots in the area. Arriving officers found three shooting victims.
A 30-year-old man was shot in the left side of his face. He is listed in critical condition.
A 29-year-old man, shot in the right leg, and a 28-year-old man, shot in the lower back, are in stable condition.
Police said they recovered a gun from the scene.
Authorities said the surveillance video shows the suspect running westbound on Market Street away from the shooting scene.
Anyone with information should call police at 215-686-3183/3184.