It happened inside USA Food Mart on East 123rd Street around 4:40 p.m.
According to police, a 60-year-old man was found in an aisle of the store with a gunshot wound to the chest. He was taken to University Hospitals where he was pronounced dead.
A 40-year-old woman was shot in the ankle, while a 30-year-old man was shot in the thigh. They both went to the hospital for treatment.
According to investigators, several customers and workers were inside the food mart when the 40-year-old and a suspect got into an argument.
Investigators say the suspect then left the store and came back with a handgun, shooting at the 40-year-old. The other victims were also hit with gunfire before the suspect run off on foot.
The shooting remains under investigation at this time.