Placement hearing for Ethan Crumbley at Oakland County circuit court in Pontiac
Ethan Crumbley, 15, who is charged with the fatal shooting of four fellow students and the wounding of seven others, including a teacher at Oxford high school on November 30, 2021, is led away from the courtroom after a placement hearing at Oakland County circuit court in Pontiac, U. Reuters

A Michigan teenager on Monday pleaded guilty to murder and terrorism charges in a mass shooting at a high school last year that killed four of his classmates and wounded more than half a dozen other people.

Ethan Crumbley, 16, is accused of opening fire at Oxford High School outside Detroit on Nov. 30 with a semi-automatic handgun that his father purchased for him as a Christmas gift days before the massacre.

Two boys, aged 17 and 16, and two girls, aged 17 and 14, were killed while six other students and a teacher were wounded.

Crumbley, who was a 15-year-old at the time of the shooting, pleaded guilty in Oakland County Circuit Court to a total of 24 charges, including one count of terrorism causing death and four counts of first-degree murder.

He was also charged with seven counts of assault with intent to murder and 12 counts of possession of a firearm in the commission of a felony.

"Ethan Crumbley's guilty plea is one small step forward on a long path towards obtaining full justice for our clients. We will continue to fight until the truth is revealed about what went wrong leading up to this tragedy," Ven Johnson, a lawyer representing several families of the victims, said in a statement.

Crumbley wore an orange jumpsuit and a white mask over his nose and mouth while his left hand remained shackled during the hearing. As he stood at the podium, he answered "Yes" to a series of questions the judge and prosecutor asked him, confirming his guilty plea.

Prosecutors told the court there was no plea agreement with Crumbley.

He faces life without parole when he is sentenced. A tentative sentencing hearing is scheduled for Feb. 9, 2023.

Crumbley's lawyers on Monday withdrew an insanity defense notice that they had previously filed with the court.

Crumbley's parents, James and Jennifer Crumbley, also face involuntary manslaughter charges connected to the shooting. In that case, Rochester District Court Judge Julie Nicholson said evidence showed they had purchased a gun for their son despite signs that he was a "troubled young man."

The case appears to be the first in the United States in which the parents of a teenage school shooter have been charged with crimes attributed to their child. They have pleaded not guilty.

Four days before the shooting, Ethan Crumbley accompanied his father to a gun shop, where James Crumbley bought a 9mm handgun, prosecutors said.