Washington DC - A man whose teenage son shot dead four people at a Georgia high school was sentenced to 15 years in prison on Thursday in a rare case of a parent convicted over a shooting carried out by their child.

Colin Gray (55) gave his son Colt the AR-15-style rifle used in the shooting as a Christmas present in 2023 despite warnings that the boy had threatened to carry out a school shooting.

Colt Gray, who is now 16, pleaded guilty to the September 2024 attack at Apalachee High School in the Georgia town of Winder and was sentenced on Tuesday to life in prison without the possibility of parole.

Colin Gray, his father, was convicted by a jury in March of second-degree murder, involuntary manslaughter, and other offenses in connection with the shooting carried out by his son, which left two 14-year-old students and two teachers dead and nine people wounded.

Celebrities Jared Leto faces barrage of new sexual assault allegations: "He has gotten away with it"

"It is clear you failed as a parent," Superior Court Judge Nicholas Primm told Gray at his sentencing hearing. "You did not provide a stable household. You didn't have him in school.

"None of those failures helped your case," Primm said. "But those aren't why you were convicted. You were convicted because the warning lights were flashing brighter and brighter and you didn't get him help and you didn't remove his access to the guns."

School shootings are a shockingly regular occurrence in the US, but parental responsibility in these shootings has come increasingly under the spotlight in recent years.

The parents of a teenager who shot and killed four people at a Michigan high school in 2021 were convicted on manslaughter charges in 2024 and sentenced to 10 to 15 years in prison in an unprecedented and closely watched case.

Jennifer and James Crumbley were the first parents of a school shooter convicted of involuntary manslaughter in the US for the actions of their child.

Colin Gray is believed to be the first parent to be charged and convicted of murder over a shooting carried out by their child.