Philadelphia police say Officer Kevin Gorman, 33, a three year veteran of the force, was treated and released at 4:45 a.m. and is expected to make a full recovery.
Officer Gorman, of the city's Mayfair section, is married with two children.
It all happened around 2:15 a.m. Friday near the 3300 block of North Howard Street near Westmoreland Street in North Philadelphia.
Authorities say Gorman was on routine patrol with his partner when they saw a car speeding the wrong way on Allegheny Avenue with four people inside.
The officers turned around and chased the car. It stopped a short time later and one person in the back seat of the car got out and ran.
Officer Gorman chased after him as the suspect climbed over a fence near Hope and Howard streets.
As Officer Gorman climbed the fence after him, there were gunshots and Gorman was hit in the shoulder with bullets from a .45 caliber weapon.
"The officer is lucky because he was turning because he saw the gun," said Lt. Ray Evers of the Philadelphia Police.
The three people who remained in the car are in custody. The shooting suspect got away and police are currently searching for him.
The three in custody do not have police records, authorities said. They are being questioned and police say they are providing information. A warrant is expected to be issued for the gunman on Friday afternoon.
"Hopefully we'll have this resolved very shortly," Lt. Evers said.
Philadelphia police radio traffic describes the suspect as a light-skinned, Hispanic male about 19-21 years old wearing a dark-colored sweatshirt and standing about 5'7". He was last seen in the alleyway near Hope and Howard streets.
Anyone with information can call Philadelphia Police at 215-686-TIPS. You can also submit a tip online.