Ethan Crumbley has withdrawn his insanity plea and pleaded guilty to killing four and wounding seven in the Oxford school mass shooting in Michigan in 2021.
16-year-old Ethan Crumbley has pleaded guilty to 24 charges in regard to a mass shooting at Oxford High School, the charges include four counts of first-degree murder and one count of terrorism causing death.
The teenage killer also pleaded guilty to seven counts of assault against the students he injured and 12 counts of criminal possession of a firearm.
Crumbley told the court that on the day of the massacre, he had taken a gun from an unlocked container at his home.
Judge Kwame Rowe has scheduled another hearing to take place on February 9, this will give the families of those killed and injured a chance to speak.
A sentencing hearing will be announced at a later date.
Prosecutors confirmed that no deals for dropped charges or a reduced sentence had been agreed prior to his guilty plea.
On November 30, 2021, Crumbley took a 9mm handgun and 50 rounds of ammunition into school hidden in his backpack.
While in the bathroom, the teenage shooter pulled out his gun and proceeded to shoot students in the hallway outside.
Officers were quickly on the scene and Crumbley surrendered without further violence.
Earlier in the day, James and Jennifer Crumbley, the killers' parents, refused to pick him up from school after teachers discovered a drawing he made of a gun, bullets, and blood, with the words: "The thoughts won't stop. Help me."
Prosecutors have accused the couple of ignoring warning signs and making their guns easily accessible for their son. Both of them are facing four charges of involuntary manslaughter.
A Michigan state prosecutor said: "Put simply, they created an environment in which their son's violent tendencies flourished.
"They were aware their son was troubled, and then they bought him a gun."
Both parents have pleaded not guilty and are being held in custody at Oakland County Jail. Their trial is due to take place in January.