Michael Freund, 49, of Aurora, was arrested at Rosie O'Reilly's located at 0N131 Gary Avenue after the shooting on Friday morning.
The DuPage County State's Attorney's Office identified the victim as Dexter Perkins.
Prosecutors say the shooting happened after a dispute arose between Perkins, Freund and two other men over a pizza and bar tab.
Perkins and one of the other men got in a scuffle outside on the front porch of the bar and Freund allegedly pulled out a 9 mm Glock from his jacket.
Prosecutors say he fired two warning shots into the air. Perkins allegedly went after the other man, which is when Freund, who was standing on the other side of a wooden railing, fired at him.
Freund fired his weapon a total of 11 times. He struck Perkins in the torso and face. Perkins was pronounced dead at the scene.
Prosecutors say Freund placed his gun in his truck's center console where it was later located by law enforcement when they arrested him.
Investigators say Perkins did not know Freund or any of the other men involved in the incident.
"Yesterday morning, Dexter Perkins lost his life allegedly over a dispute regarding pizza and a bar tab," Berlin said. "For this senseless act of violence that resulted in the death of an innocent man, Mr. Freund now finds himself facing first degree murder charges.
Freund appeared in court Saturday morning and was charged with one count of first degree murder. He was also denied pre-trial release.
"It’s horrible to see this type of violence occur during the holiday season," Mendrick said.
Freund’s next court appearance was scheduled for January 18.