Surveillance video shows the suspect walking into the Lancaster Hoagie City Deli in the 600 block of North 40th Street.
He grabs a 22-year-old man from behind, trying to rob him.
A scuffle ensues, and a licensed handgun belonging to the victim falls to the ground.
The suspect grabs the weapon, fires a shot at the victim, missing him, then runs off.
The victim gave chase, but then lost sight of the suspect.
The suspect is described as a black man with a dark complexion in his early 20s, 5'9 -5'10" tall.
He is seen in the video wearing a plaid checkered shirt with a red or orange colored shirt underneath, and a red baseball cap.
Anyone with information about this crime or suspect is asked to contact Philadelphia Police Detective Pearson at 215-685-3183/3184.