Officers say the suspect opened fire on the man on the 3800 block of Melon Street in the Mantua section of the city.
When police arrived they found the victim lying in the street with a bullet wound to the head. He was pronounced dead at the Hospital of the University of Pennsylvania.
Police have identified the victim as 21-year-old Archie Coleman from the 3200 block of Mantua Street.
So far, police have not indicated that they have any suspects or motives.
