T.J. Lane was charged Thursday afternoon on six counts related to Monday's shooting at Ohio's Chardon High School - three counts of aggravated murder, two counts of attempted aggravated murder and one count of felonious assault, according to court documents. The charges were filed in juvenile court.

Lane, a 17-year-old sophomore, has confessed to taking a .22-caliber gun and a knife to the school and firing 10 rounds as scared students and teachers ran for cover, according to the prosecutor.

– CNN's Laura Dolan contributed to this report.