A school shooter who killed two students and two teachers in Georgia has pleaded guilty to 55 counts.Colt Gray, 16, entered the plea Friday without having reached a deal with prosecutors. He had previously pleaded not guilty to charges in the Sept. 4, 2024, shooting at Apalachee High School that killed four people and left several others wounded about 45 miles (73 kilometers) northeast of Atlanta.Barrow County Superior Court Judge Nicholas Primm is now set to hear each side’s summary of the case, evidence and sentencing recommendation before deciding the sentence.Gray’s trial had been scheduled to start in mid-October in Columbia County, about 100 miles (160 kilometers) from where the shooting happened, after the judge agreed to a defense request for a change of venue.Colin Gray, the father of Apalachee High School shooter Colt Gray, enters the Barrow County courthouse for his first appearance, on September 6, 2024 (Getty Images)A jury in March convicted his father, Colin Gray, on charges including second-degree murder and involuntary manslaughter, and he is scheduled to be sentenced next week. Prosecutors said the elder Gray gave his son the assault-style rifle used to open fire at the school.Teachers Richard “Ricky” Aspinwall, 39, and Cristina Irimie, 53, and students Mason Schermerhorn and Christian Angulo, both 14, died in the shooting. Another teacher and eight more students were wounded, seven of them hit by gunfire.