Crumbley had no discipline issues at the school prior to the shooting, but his behavior earlier that day raised flags. A teacher had discovered a drawing with a gun pointing at the words: “The thoughts won’t stop. Help me.” There was an image of a bullet with the message: “Blood everywhere.”

According to investigators, Crumbley’s parents declined to take him home that day. They were told to get him into counseling within 48 hours.

A day before the shooting, a teacher had seen Crumbley searching for ammunition on his phone. The school reached out to his mother, who the prosecutor’s office said texted Crumbley: “Lol. I’m not mad at you. You have to learn not to get caught.”

Crumbley’s guilty plea comes as his parents face involuntary manslaughter charges for their alleged role in the Michigan high school shooting. They are accused of making a gun accessible to their son and ignoring his need for mental health treatment.

The Crumbleys said they were unaware of Ethan’s plan to commit a school shooting. They also dispute that the gun was easy to grab at home.

The Associated Press contributed to this report.