Washington (AFP) - The mother of a teenage boy who shot dead four students at his Michigan high school took the stand on Thursday at her high-profile trial on involuntary manslaughter charges.

Jennifer Crumbley and her husband, James, are the first parents of a school shooter to face felony charges in the United States for the actions of their child, according to prosecutors.

Ethan Crumbley, 17, their son, is serving a life sentence for the November 30, 2021 shooting at Oxford High School which left four students between the ages of 14 and 17 dead and six students and a teacher wounded.

The Crumbleys are accused of buying their son the 9mm SIG Sauer handgun he used to carry out the shooting and ignoring warnings he had mental health struggles.

James Crumbley is to be tried separately in March.

Jennifer Crumbley testified that her husband bought their son the gun just days before the attack as an early Christmas present, and she took the boy to a shooting range the next day.

She said her husband was responsible for storing the weapon at their home, and it was for her son "to use at the shooting range only."

Crumbley told the jury she never had any exchanges with her son's teachers about discipline issues although he frequently failed to hand in homework assignments and his grades were poor.

She said Ethan was anxious about what he was going to do after high school "but not to a level where I felt he needed to go see a psychiatrist or mental health professional."

Asked about their relationship, Crumbley said: "I thought we were pretty close. We would talk. We did a lot of things together. I trusted him and I felt like I had an open door and he could come to me about anything."

'Alarmed'

She said she never had any reason to believe her son was capable of carrying out such a violent act.

"As a parent, you spend your whole life trying to protect your child from other dangers," Crumbley said. "You never would think you have to protect your child from harming somebody else.

"That was the hardest thing I had to stomach, that my child hurt other people," she said. "I wish he would have killed us instead."

While school shootings carried out by teens have become part of American life, it is unprecedented for parents to face charges.

The Crumbleys were summoned to the school on the day of the shooting after a teacher was "alarmed" by a drawing 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 a bathroom, emerged with the gun which had been concealed in his backpack and fired more than 30 shots.

The father of an Illinois man accused of killing seven people in July 2022 pleaded guilty in November to misdemeanor charges of "reckless conduct" for helping his son obtain the assault rifle used in the mass shooting.

A conviction for involuntary manslaughter carries a maximum sentence of 15 years in prison.