A Georgia man whose 14-year-old son killed two students and two teachers at Apalachee High School in September 2024 was convicted Tuesday of second-degree murder and involuntary manslaughter.

Jurors reached the verdict in less than two hours, finding Colin Gray guilty of all charges. He remained largely emotionless as the verdict was read and as each juror was polled, and deputies subsequently handcuffed him. Sentencing will be scheduled at a later date.

Gray was convicted of second-degree murder in the deaths of students Mason Schermerhorn and Christian Angulo, both 14. Under Georgia law, second-degree murder includes causing the death of a child through cruelty. He was also found guilty of involuntary manslaughter in the deaths of teachers Richard Aspinwall, 39, and Cristina Irimie, 53. Another teacher and eight students were wounded during the attack. Gray also faced multiple counts of reckless conduct and cruelty to children.

Prosecutors said Gray provided his son, Colt Gray, access to a semiautomatic rifle and ammunition despite being warned that Colt could harm others. The teen’s mother, Marcee Gray, testified that she had urged Colin Gray to secure the firearms in his truck but declined to comment after the verdict.

Investigators detailed that Colt Gray carefully planned the Sept. 4, 2024, attack. He brought the rifle onto the school bus, concealing it in his book bag with poster board, then carried out shootings in classrooms and hallways. Prosecutors said Colin Gray had purchased the gun for his son the previous Christmas and was aware of his deteriorating mental health and fascination with past school shooters, including a shrine to Nikolas Cruz.

Colt Gray faces 55 charges, including murder, and has pleaded not guilty. A status hearing is scheduled for mid-March. The case underscores growing legal scrutiny on parents whose children commit fatal school shootings.