LITTLE ROCK, Ark. (AP) — A murder trial has begun for an Arkansas man accused of firing his gun into another driver's car and killing a 3-year-old boy who was in the back seat.

Gary Eugene Holmes is charged with first-degree murder in the December 2016 death of Acen King. The boy's grandmother says she was stopped at a stop sign when Holmes honked his horn, got out of his car and fired into her car.

According to a police affidavit, a woman who was in Holmes' car told investigators that he was angry because he thought the car behind him was tailing him too closely.

The Arkansas Democrat-Gazette reports that Holmes' attorney, Ron Davis, told the Little Rock jury on Tuesday that Holmes' gun went off inadvertently and that he didn't intend to fire it.

Deputy prosecutor Tracye Mosley told jurors the shooting wasn't an accident.