WINDER, Ga. (AP) — A Georgia man whose teenage son is accused of killing two students and two teachers at a high school was convicted of second-degree murder and involuntary manslaughter Tuesday.

Colin Gray also was found guilty of all other charges in the September 2024 shooting at Apalachee High School in Winder, northeast of Atlanta. Gray is one of a number of parents across the country who have been charged after their children were accused in fatal shootings.

He showed little emotion as he watched each juror being polled by the judge. Deputies then handcuffed him behind his back as he stood at the defense table, consulting with his lawyer. He will be sentenced at a later date.

Colin Gray was found guilty of second-degree murder in the deaths of two 14-year-old students, Mason Schermerhorn and Christian Angulo. Georgia law defines second-degree murder as causing the death of a child by committing the crime of cruelty to children. Gray was found guilty of involuntary manslaughter in the killings of teachers Richard Aspinwall, 39, and Cristina Irimie, 53.

Prosecutors said Gray gave his son, Colt, access to a gun and ammunition “after receiving sufficient warning that Colt Gray would harm and endanger the bodily safety of another.”

Colt Gray, who was 14 at the time of the shooting, was indicted on a total of 55 counts, including murder. He has pleaded not guilty and the judge in his case has set a status hearing for mid-March.

Investigators said Colt Gray carefully planned the Sept. 4, 2024, shooting at the school attended by 1,900 students.

He boarded the school bus with a semiautomatic, assault-style rifle in his book bag, the barrel sticking out and wrapped in poster board, investigators said. He left his second-period class and emerged from a bathroom with the gun and then shot people in a classroom and hallways, investigators said.

Colin Gray had given his son the gun as a gift the Christmas before the shooting and allowed him to have access to the gun and ammunition, despite his awareness that his son’s mental health had deteriorated, a prosecutor said.

Colin Gray knew his son was obsessed with school shooters, even having a shrine in his bedroom to Nikolas Cruz, the shooter in the 2018 massacre at Marjory Stoneman Douglas High School in Parkland, Florida, prosecutors said.