The 15-year-old suspect accused of killing four of his classmates in a shooting at Oxford High School in Michigan recorded several videos on his cell phone the night before the attack. Oakland County Sheriff's Lt. Tim Willis told a judge the teen talked "about shooting and killing students the next day at Oxford High School."
Willis said that investigators also recovered a journal in which the suspect, identified as Ethan Crumbley, detailed his plan to "deliberately murder as many students as he could that day."
Investigators also reviewed surveillance footage from inside the school, which showed Crumbley stalking his fellow classmates as he gunned them down.
"He methodically and deliberately walked down a hallway, aimed the firearm at students, and fired it," Oakland County Assistant Prosecutor Marc Keast said. "After children started running away from the defendant, he continued down the hallway, again at a deliberate and methodical pace, pointing and aiming inside classrooms and at students who hadn't had the opportunity to escape."
Authorities have yet to determine a motive for the massacre.
His parents were called into a meeting with school officials hours before the shooting to discuss behavioral issues their son was having. Officials did not provide specific details about those issues or what was discussed at the meeting.
Crumbley was charged as an adult with one count of terrorism causing death, four counts of first-degree murder, seven counts of assault with intent to murder, and 12 counts of possession of a firearm in the commission of a felony. He was denied bail and was transferred to the Oakland County jail.