(NewsNation) — A 12-year-old boy in Michigan fired a gun while robbing a gas station, police say. The whole thing was caught on video.

Hartford, Michigan, police say the preteen told them he stole the gun from his grandfather’s locked safe, but his grandfather — who also happens to be his legal guardian — told police he had no idea his grandson could access the safe.

According to police, the boy walked into a Marathon gas station last Wednesday afternoon. He stood in line behind another customer. Once that customer left, the kid pulled out a handgun, demanded money and fired a warning shot into the air.

The clerk told police she thought it was a joke at first, but she handed the boy a bag filled with around $5,000 so he would leave the store.

The boy quickly ran off, but police caught up with him a few minutes later and arrested him.

He’s at a juvenile detention center and will be held there until a hearing later this month. The 12-year-old has been charged with six felonies including armed robbery, discharging a firearm and assault with a dangerous weapon.