A man is accused of throwing a mountain bike at a woman, who is believed to be his girlfriend, outside a Mesa grocery store on Tuesday, police said.

Brian Kirby, 31, was seen fighting with the woman outside Safeway near University Drive and Lindsay Road at about 4:45 p.m. before hitting her with the tossed bike, police said.

Officers attempted to contact Kirby, who fled to the back of the store and ran into an employees-only area, according to police. Police said Kirby attempted to run out an exit but could not because of the door's delay device.

When he was approached by an officer, Kirby pulled out a Glock handgun and ran, throwing the gun into a cardboard baler as he fled, according to police.

Kirby was taken into custody near the main entrance of the store and identified himself as Chris Kirby, which officers discovered to be his brother's name, police said.

He was arrested on suspicion of misconduct involving a weapon, false reporting to an enforcement officer, and second-degree criminal trespass, according to a court document.

Officers later discovered that the gun had a round of ammunition in the chamber and additional rounds in the magazine, according to the court document.