An Arkansas man was sentenced Wednesday to 50 years in prison without the possibility of parole after fatally shooting a 3-year-old in a road-rage incident.

Gary Eugene Holmes was convicted of first-degree murder and terroristic threatening after a jury found him guilty of the December 2016 killing of Acen King.

According to the boy’s grandmother, Kim King-Macon, she was stopped at a stop sign in Little Rock, when Holmes honked his horn, got out of his car and fired into her car. King was shot in the back but his grandmother did not realize until she reached a shopping center 10 miles away.

The toddler died later that night at the hospital.

A woman who was in Holmes’ car at the time of the shooting had a different story. According to a police affidavit, she said he was angry because he thought the car behind him was tailing him too closely.

Jurors deliberated for fewer than 30 minutes before returning the guilty verdict. Holmes was sentenced 45 years for the killing and five years for the terroristic threats.

Holmes’s mother said she didn’t think her son was “in his right mind” when he shot at the vehicle. She also described injuries her son sustained as a child and battles with depression.

Defense Attorney Ron Davis said Holmes plans to appeal.

The Associated Press contributed to this report.