A Georgia grand jury indicted both a father and son on murder charges Thursday in a mass shooting at Apalachee High School in Winder.

Georgia media outlets reported that the Barrow County grand jury meeting in Winder indicted 14-year-old Colt Gray on Thursday on a total of 55 counts including four counts of malice murder, 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.

Deputy court clerk Missy Headrick confirmed that Colin and Colt Gray had been indicted in separate indictments. She said the clerk's office had not yet processed the indictments and that the documents likely wouldn't be available to the public until Friday.

Both are scheduled to appear for arraignment on Nov. 21, when each would formally enter a plea. 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 in Gainesville. Neither has sought to be released on bail and their lawyers have previously declined comment.

Investigators testified Wednesday during a preliminary hearing for Colin Gray 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 up 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 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, seven of them hit by gunfire.

Investigators have said the teenager carefully plotted the shooting at the 1,900-student high school northeast of Atlanta. A Georgia Bureau of Investigation agent testified that the boy left a notebook in his classroom with step-by-step handwritten instructions to prepare for the shooting. It included a diagram of his second-period classroom and his estimate that he could kill as many as 26 people and wound as many as 13 others, writing that he'd be "surprised if I make it this far."

There had long been signs that Colt Gray was troubled.

Colt and Colin Gray were interviewed about an online threat linked to Colt Gray in May of 2023. Colt Gray denied making the threat at the time. He enrolled as a freshman at Apalachee after the academic year began and then skipped multiple days of school. Investigators said he had a "severe anxiety attack" on Aug. 14. A counselor said he reported having suicidal thoughts and rocked and shook uncontrollably while in her office.

Colt's mother Marcee Gray, who lived separately, told investigators that she had 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 shooting 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, an investigator said.

Colin Gray's indictment is 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.

"In this case, your honor, he had primary custody of Colt. He had knowledge of Colt's obsessions with school shooters. He had knowledge of Colt's deteriorating mental state. And he provided the firearms and the ammunition that Colt used in this," District Attorney Brad Smith told the judge Wednesday at the preliminary hearing.