The gunman fired at least 15 shots along the unit block of Collom Street in the city's Germantown section around 6:30 p.m. on Monday.
A man in his 20s was shot in the stomach. He was taken to Einstein Medical Center in critical condition.
Police say bullets also hit several parked cars.
According to investigators, the gunman called police after the shooting, explaining the victim had stolen his scooter earlier in the day.
Police say one person is in custody. No charges have been filed.
The incident remains under investigation.