Colin Gray, the father of the Georgia teenager who carried out the 2024 Apalachee High School shooting, was sentenced to 15 years in prison after being convicted of second-degree murder and other charges.

Prosecutors argued that Gray ignored warning signs about his son’s behavior and provided the AR-15-style rifle used in the attack that killed four people and injured others.

His son, Colt Gray, was previously sentenced to life in prison without parole after pleading guilty to all charges related to the shooting.

The case marks one of the first times in the U.S. that a parent has been held criminally responsible for a child’s mass shooting, drawing comparisons to other cases involving parents of school shooters, ABC News has reported.

The judge said the tragedy could have been prevented if Gray had secured the weapon or acted on the warning signs surrounding his son.