It happened on February 1 near Broad and Oxford streets around 9 p.m.
Police say a man and woman inside the store were being rude to employees and that's when two security guards employed by Rite Aid interfered and asked them to leave.
One of the guards, a 41-year-old man, reportedly walked the couple out of the store to a nearby parking lot in the back of an AMC Theatre where an altercation ensued.
SEE ALSO: Philadelphia Rite Aid security guard shot in parking lot after altercation with customer: Police
Rite Aid security guard shot after altercation with customer: Police
"We believe it could have been a fistfight, and the gentleman who was arguing in the store pulls out a gun and fires one shot, hitting the (security guard) in the foot," Philadelphia Police Captain John Walker said.
The security guard suffered non-life-threatening injuries.
Police say the suspect was able to get away.
On Thursday, police released video of the alleged gunman wearing a "Florida Marlins" hat inside the Rite Aid store.
The video also shows the suspects leaving the parking lot in a gold or silver SUV.
Anyone with information is asked to call police at 215-686-TIPS.