The slain officer was identified as Moses Walker Jr. - a 19-year-veteran of the force.
The shooting happened around 5:55 Saturday morning on the 2000 block of Cecil B. Moore Avenue near Woodstock Street.
Police say Officer Walker was walking down Cecil B. Moore Avenue when he was approached by an unknown assailant.
The 22nd district officer was shot multiple times with at least one shot to the chest.
Arriving police officers found the Walker lying in the street. He was taken to Hahnemann Hospital where he was later pronounced dead.
According to authorities, the he had just finished his shift overnight and was not wearing his uniform.
Police say the Officer Walker removed his weapon from its holster but are not sure if he was able to fire it. The weapon was later recovered underneath his body.
Police Commissioner Charles Ramsey says this tragic loss is especially hard for fellow officers.
"It's tough, we literally just removed our mourning bands from our badges last week for Officer Lorenzo and now we're putting them back on. This department has been through a lot. In the 4 ½ years I've been here this will be the 7th officer we've lost which is more than some departments get in 20 years," said Commissioner Ramsey.
Meanwhile a motive has not been named. Police say the suspect fled through a vacant lot shortly after the shooting
Police are searching the area on the 2000 block of Cecil B. Moore with K-9 dogs for a possible suspect.
Anyone with information is urged to immediately contact Philadelphia Police.