The driver, Timothy Saunders, 53, is being held without bond.
Witnesses at American Freight Liquidators near Wolfchase Galleria said Saunders got into an argument with dock manager Thomas Hartman over why his truck was not unloaded. As the argument escalated, Saunders left, returned with a pistol and shot Hartman in the head.
Hartman, 41, of Nesbit, Miss., was pronounced dead at the scene.
Saunders drove off in his red tractor trailer after the shooting, but he was stopped and arrested a short time later.
The case is being handled by Senior Felony Asst. Sarah Poe of the DA’s Vertical Prosecution Team 4 which handles cases from General Sessions Division 12 and Criminal Court Division 4.