CLEVELAND (WJW) — A 22-year-old Cleveland man was shot in the head during an argument with a gas station security guard early Wednesday morning, Cleveland police said.

It happened just before 1 a.m. at the Marathon gas station in the 2700 block of East 116th Street, near the Methyl Avenue intersection, according to Cleveland police. Gunshot detectors alerted police to the area.

Witnesses told police they saw the store’s security guard, a 25-year-old Warrensville Heights man, arguing with the man.

Security camera footage shows the security guard retrieving a semi-automatic rifle from a parked vehicle and using it to shoot the 22-year-old in the head near the front door of the gas station, police reports say. The guard then left the gas station in a vehicle.

First responders found the 22-year-old and transported him to a hospital in “serious condition,” according to police.

The security guard later told detectives he would turn himself in, according to a police report. He is not currently listed as an inmate in the Cuyahoga County jail. Court records do not list any charges for him.