Tampa police said the victim, a 77-year-old man, went through the drive-thru at the Dunkin Donuts location at 410 South 50 Street on May 5.
The unidentified man became upset about the lack of service, and was asked by staff members to leave without being served.
Instead, police said the victim parked his car and went inside the restaurant to argue with 27-year-old employee Corey Pujols.
(Tampa Police Dept.)
Investigators said the victim called Pujols a racial slur and repeated the phrase after Pujols challenged him to do so.
That's when police said Pujols punched the victim in the jaw, knocking the man out and causing him to fall and hit his head on the floor.
Tampa Fire Rescue responded and transported the victim to the hospital, where he died two days later.
Police arrested Pujols and charged him with aggravated manslaughter of an elderly adult.