Police say the 60-year-old retired corrections officer was opening the store when he was approached by the suspect, who announced a robbery.
A struggle ensued, during which the retired corrections officer fired numerous shots, according to police.
Authorities believe the suspect was hit by the gunfire because a large amount of blood was found at the scene.
The suspect escaped the store with a bag of money, believed to be about $30,000, police said. He fled on foot and then jumped into a red car. Authorities were also looking for a white Ford Explorer, driven by a woman, that sped off towards the Long Island Expressway.
Surveillance video was seized from a nearby ATM as investigators pieced together the robbery, which appeared to be a planned hit.
The retired corrections officer, who hung up his badge in 1996, was not injured.
