James Crumbley, the father of a Michigan teen who used a gun bought by his parents to fatally shoot four students, was convicted of involuntary manslaughter in a US court on Thursday.

Crumbley, 47, was found guilty by a jury a month after his wife, Jennifer Crumbley, was convicted on manslaughter charges.

Both parents face up to 15 years in prison.

Their son, Ethan, shot and killed four students at Oxford High School in 2021 with a semi-automatic handgun. 

Jennifer Crumbley had testified in her trial that James had bought their son the gun as an early Christmas present.

Ethan was 15 at the time of the shooting. He is currently serving a life sentence.

How the events unfolded

On the day of the shooting, the Crumbleys were called by the school after a teacher found a violent drawing on Ethan's desk.

The parents were advised to get counseling, but they allegedly resisted taking their son home and he returned to class.

Later, he fired more than 30 shots with a gun he had concealed in his backpack. He killed four students while injuring six more and a faculty member.

Prosecutors: Parents ignored Ethan's mental health warnings

During the trial, defense attorney Mariell Lehman said James Crumbley did not know what his son was about to do. "He did not know he had to protect others from his son," Lehman said.

In excerpts of Ethan's journal seen by the jury, the boy wrote that he wanted help but his parents were not listening to him.

"I have zero help for my mental problems and it's causing me to shoot up the ... school," Ethan wrote.

Prosecutor Karen McDonald said the boy's parents ignored Ethan's mental health warnings and by not securing the firearm, James "didn't just fail his son. He failed to perform his legal duty to prevent these kids from being killed."

'Doing very little about gun violence'

This is the first case in the United States where parents were legally held accountable for their child's school shooting.

Gun safety experts hope this case serves as a wake-up call for parents, with research showing about 75% of school shooters obtained weapons from their own homes.

Steve St. Juliana, father of one victim, said more needs to be done to address gun violence.

"Our children are dying on a daily basis in mass murders, and we do very little about it," he said.

ss/sms (AP, AFP, Reuters)