ATLANTA — A Georgia grand jury has indicted a father and son in a mass shooting at Apalachee High School in Winder.

WAGA-TV, among other media, reported that the Barrow County grand jury meeting in Winder indicted 14-year-old Colt Gray on Thursday on 55 counts, including four counts of malice murder and four counts of felony murder, plus aggravated assault and cruelty to children. His father, Colin Gray, faces 29 counts, including second-degree murder, involuntary manslaughter and reckless conduct.

Both are scheduled to appear for arraignment on Nov. 21. Colin Gray is being held in the Barrow County jail. Colt Gray is charged as an adult but is being held in a juvenile detention center.

Investigators testified that Colt Gray carried a semiautomatic assault-style rifle on the school bus that morning, with the barrel sticking out of his book bag wrapped in a poster board. They say the boy left his second-period class and emerged from a bathroom with the rifle before shooting people in a classroom and the hallways.

The shooting killed teachers Richard Aspinwall, 39, and Cristina Irimie, 53, and students Mason Schermerhorn and Christian Angulo, both 14. Another teacher and eight more students were wounded.

Investigators have said the freshman carefully plotted the shooting at the 1,900-student high school northeast of Atlanta. A Georgia Bureau of Investigation agent testified that Colt Gray left a notebook in his class with step-by-step handwritten instructions for how to prepare for the shooting.

Colt Gray’s mother, Marcee Gray, who lived separately, told investigators she argued with Colin Gray, asking him to secure his guns and restrict Colt’s access in August. Instead, he bought the boy ammunition, a gun sight and other accessories, records show.

After Colt Gray asked his mother to put him in a “mental asylum,” the family arranged to take him on Aug. 31 to a mental health treatment center in Athens that offers inpatient treatment, but the plan fell apart when his parents argued about Colt’s access to guns the day before and his father said he didn’t have the gas money to take him to the center, an investigator said.

Colin Gray’s arrest was the latest example of prosecutors holding parents responsible for their children’s actions in school shootings. Michigan parents Jennifer and James Crumbley, the first to be convicted in a U.S. mass school shooting, were sentenced to at least 10 years in prison for not securing a firearm at home and acting indifferently to signs of their son’s deteriorating mental health before he killed four students in 2021.