Police said the 27-year-old man was shot multiple times just before 6 a.m. Sunday in south Philadelphia.
Officials said he was pronounced dead on the way to the Hospital of the University of Pennsylvania.
WPVI-TV says responding officers began chasing a vehicle with four men inside through south Philadelphia.
Police said one of the passengers threw a gun out, and the vehicle was stopped shortly afterward and three men arrested. A fourth man is being sought.
The identity of the victim was not immediately released and other details were not released.