A driver for food delivery app Uber Eats shot and killed a customer in Atlanta over the weekend.

NPR reports 30-year-old Ryan Thorton, a recent Morehouse College graduate went outside on Saturday night to retrieve his food from the deliverer. As Thorton began walking away from driver Robert Bivines, a verbal altercation ensued. When Thorton began walking towards the 37-year-old’s car, he shot the man four times from his Volkswagon before speeding off.

Thorton was transported to a hospital where he later died. Bivines, who’d been driving for the company for a week, turned himself into police on Monday. Bivnes’ attorney Jackie Patterson told WSB-TV his client acted in self-defense. He said Thorton was upset the food had taken so long and Bivines felt threatened.

“He turned around put his hand in his pocket and said, ‘I’m going to (bleep) you up,'” Patterson said. “You can’t drive away when someone is coming at you with your window down.”

The Atlanta Journal Constitution reports Bivines was convicted of battery in 2010. Uber’s criminal background check only looks for offenses that occurred within the past seven years. Atlanta police are investigating the incident and Uber is reportedly cooperating with the department. Uber representative Andrew Hasbun told NPR the company was taken aback by news of the shooting.

“We are shocked and saddened by this news,” Hasbun said. “We are working with the Atlanta Police Department, and our hearts go out to the families of those involved.”

Thorton just graduated from Morehouse with a degree in political science in May and recently began a new job. The fatal incident comes just months after a 16-year-old Atlanta-area girl accused her 58-year-old Abdoulie Jagn, who was Uber driver at the time, of raping her.