A waitress at a Waffle House in Biloxi, Mississippi, was shot in the head early Friday morning, the Sun Ledger reports, after she asked a customer to put out his cigarette.

Biloxi police Sergeant Donnie Dobbs said Johnny Max Mount, 45, shot Julie Brightwell, 52, with a 9mm handgun around 1 a.m. Friday morning. She died at Merit Health Biloxi. According to the Sun Ledger, Brightwell had been working at Waffle House for eight years.

Mount was arrested shortly after the shooting and charged with first-degree murder. His bond has been set at $2 million.

“The individual was still sitting there and they took him into custody,” Dobbs told the Clarion Ledger. “Upon investigation we learned he had gotten into an argument with an employee over smoking and he pulled out a handgun and shot the employee in the head.”

Mount, who worked as a Biloxi firefighter for a decade, suffered a traumatic brain injury in 2002, the Sun Herald reports, when he was hit by a car, while standing in the middle of the road, around 2:30 a.m. on Christmas Eve. He also lost a limb. From the Herald:

Fire Chief Joe Boney said Friday he had been a good employee, but that he hadn’t kept up with Mount since he left shortly after his accident in 2002. Still, he said, “it’s unbelievable that this happened.” “I don’t know what would happen to push him to that,” Boney said. “It’s just one of those things that is incomprehensible to me. It’s a tragedy for both families. We pray that he can get the help he needs if he needs it. Obviously, he does.”

“I just don’t understand why somebody would be so upset over a cigarette,” Biloxi Police Chief John Miller said. “Some stuff like this just defeats logic.”