The shooting happened around 6:30 p.m. Monday at the KFC restaurant in the 5000 block of Delmar Boulevard in the Central West End neighborhood.
Investigators say a suspect was in the drive-thru of the restaurant when he tried to place an order, and one employee informed him the business was out of corn. After that, the suspect reportedly made threats toward the employee from the speaker box.
A short time later, the suspect pulled up to a drive-thru window with a handgun, police say. A 25-year-old employee went outside to talk with the driver, then he returned to the restaurant with a gunshot wound.
Police say the victim is in critical, but stable condition and remained hospitalized Tuesday.
The suspect took off from the restaurant after the gunfire. Police say the suspect, who was last seen wearing a blue jean jacket with a gray hood and sleeves, is a Black man in his 40s or 50s, with a thin build and a scruffy beard.
The St. Louis Metropolitan Police Department is handling the investigation.