ATLANTA– A judge set a plea and sentencing hearing for later this month for a teenager accused of killing four people in a September 2024 shooting at Apalachee High School in Georgia.

Colt Gray, 16, had pleaded not guilty to charges including murder in the shooting that killed two students and two teachers, and left several others wounded, at the high school northeast of Atlanta.

In a court filing Friday, the judge overseeing his case set a “Non-Negotiated Plea and Sentencing Hearing” to begin July 24. The judge had previously said that if Gray wanted to plead guilty before trial, he had to notify the state and the court next Wednesday.

A non-negotiated plea means that the State and the defense have not reached an agreement on a sentence. Unlike a negotiated plea, or plea agreement, where a defendant makes a deal with prosecutors to plead guilty in exchange for an agreed upon sentence and possibly a reduction in charges, this leaves sentencing entirely in the hands of the judge, who makes a decision after giving each party the opportunity to present a summary of the case and a sentencing recommendation.

Colt Gray’s attorney did not immediately respond to an email seeking comment Sunday.

Gray’s trial had begun in mid-October in Columbia County, about 100 miles (160 kilometers) from Barrow County where the shooting occurred, after the judge granted a defense request to change the venue.

Gray’s father, Colin Gray, was convicted by a jury in March on charges including second-degree murder and manslaughter after prosecutors said he gave his teenage son the assault rifle used to open fire at the school. The elder Gray will be sentenced later this month.

The Sept. 4, 2024, shooting killed teachers Richard “Ricky” Aspinwall, 39, and Cristina Irimie, 53, and students Mason Schermerhorn and Christian Angulo, both 14. Another teacher and eight more students were injured, seven of them hit by gunfire. Colt Gray, who was 14 at the time of the shooting, was charged as an adult with 55 counts in total, including murder, cruelty to children and 25 counts of aggravated assault.

Investigators testified that Colt Gray carried the rifle his father gave him to the school bus with the barrel wrapped in cardboard. They said the teen left his second period class and came out of a bathroom with the rifle, shooting at people in a classroom and in the hallway.

Investigators have said the teenager carefully planned the shooting at the 1,900-student high school. A Georgia Bureau of Investigation agent testified that the boy left a notebook in his classroom with step-by-step instructions and a diagram for preparing for the assault, including an estimate that he could kill up to 26 people and injure up to 13 more.

Colt and Colin Gray were interviewed by sheriff’s deputies about an online threat linked to Colt Gray in May 2023. Colt Gray denied making the threat at the time. He skipped eighth grade, enrolled as a freshman at Apalachee after the academic year began, and then skipped several days of school.

Family members had been seeking psychological help for Colt Gray before the shooting, but it appeared he never saw a counselor.

Colt’s mother, Marcee Gray, who was separated from Colin Gray, told investigators that she had argued with Colin Gray weeks before the shooting, asking him to secure his guns and restrict Colt’s access. Instead, over time, he bought the boy ammunition, a gun scope and other shooting accessories, records show.

Colt Gray even created a shrine in his bedroom for Nikolas Cruz, the shooter in the 2018 massacre at Florida’s Marjory Stoneman Douglas High School, prosecutors said.