Washington (AFP) - A 16-year-old boy pleaded guilty on Monday to shooting dead four students at his Michigan high school in a case that has drawn national attention because his parents are also facing charges.

Ethan Crumbley, who was 15 years old at the time of the November 30, 2021, shooting but was charged as an adult, faces a potential sentence of life in prison.

"Is it your own choice to plead guilty?" Oakland County Circuit Judge Kwame Rowe asked Crumbley in a televised court appearance.

"Yes sir," replied the lanky teenager, who was wearing an orange prison jumpsuit, black glasses and a face mask.

Prosecutors then walked him through the day of the shooting, with Crumbley admitting that he brought a 9mm Sig Sauer handgun and 50 rounds of ammunition to Oxford High School, north of Detroit.

He acknowledged entering a boy's bathroom, removing the gun from his backpack and opening fire on his fellow students.

Four classmates between the ages of 14 and 17 were killed and six other students and a teacher were wounded.

Crumbley faced first-degree murder and terror charges.

During the half-hour court appearance, the boy said he gave his father the money to purchase the gun used in the shooting.

Crumbley's parents, James and Jennifer Crumbley, have been charged with involuntary manslaughter and are scheduled to go on trial next year.

While school shootings carried out by teens have become a sadly familiar part of American life, it is highly unusual for parents to face charges.

'My new beauty'

The Crumbleys are accused not only of supplying their son with a weapon, but of ignoring escalating warnings that he appeared to be on the brink of violence.

James Crumbley allegedly bought the handgun for his son and his wife took the boy to a shooting range just days before the attack.

Ethan was with his father at the time of the purchase at a local firearms store and the teen posted a picture of the gun on his Instagram account, writing "just got my new beauty today" along with a heart emoji.

The Crumbleys were summoned to the school on the day of the shooting after a teacher was "alarmed" by a note she found on Ethan's desk.

The parents were shown the drawing and advised they needed to get the boy into counseling.

They allegedly resisted taking their son home and he returned to class.

He later entered the bathroom, emerged with the gun which had been concealed in his backpack and fired more than 30 shots.