A Michigan mother, Jennifer Crumbley, aged 45, has been convicted of involuntary manslaughter by a jury for her failure to intervene in her son's deadly school shooting.

This marks the first instance in the United States where a parent has been found guilty of manslaughter in connection with a mass shooting committed by their child.

Prosecutors alleged negligence on her part for allowing her son access to a firearm and disregarding warning signs. Her husband, James, faces a separate trial on identical charges and has pleaded not guilty.

Their son, currently 17, is serving a life sentence for murdering four classmates at Oxford High School in Michigan on November 30, 2021. Additionally, seven individuals were wounded in the shooting.

During the reading of the verdict in Oakland County court on Tuesday, Ms. Crumbley appeared devoid of emotion and maintained a steady gaze downwards. She faced four counts of involuntary manslaughter, each carrying a maximum sentence of 15 years.

Several relatives of the victims expressed relief at the verdict, with Buck Myre, father of Tate Myre, a 16-year-old victim, stating, "The People spoke!" He emphasized the importance of the legal process.

At the core of the trial was the question of whether the mother could have anticipated and prevented the tragic incident. The Crumbleys purchased the firearm used by their son just days before the shooting and were promptly charged by law enforcement after the event.

Despite initially being scheduled for a joint trial, the parents opted for separate trials, with James Crumbley set to face trial in March. Prosecutors presented evidence suggesting that Ethan Crumbley had sought mental health assistance and exhibited signs of distress, which his parents allegedly disregarded. Ms. Crumbley, however, testified that she did not perceive her son as having mental health issues.

On the day of the shooting, the parents left a school meeting regarding a troubling drawing made by their son to attend work, declining to take the 15-year-old home. School officials, unaware of the contents of his backpack, allowed him to return to class, where he carried out the deadly attack.

Some experts have suggested the cases against the Crumbleys could lead to more charges for parents of children who commit mass shootings.

Stephen J Morse, a professor of law and psychiatry at the University of Pennsylvania, said he disagreed with the verdict, arguing that because Ethan Crumbley had pleaded guilty, he was the only one responsible for the shooting.

"I understand that she was not necessarily the best mother in the world, but this is not a crime," he said.

Mr Morse said he believed the decision could set a bad precedent, causing courts to look for "scapegoats" in similar situations.

Others say this case was so unusual that it is unlikely to have wider ramifications.

"I don't fear that this is going to open the floodgates to parents being charged in a run of the mill case if there is such a thing," said Frank Vandervort, a University of Michigan clinical professor of law.

"I think the facts of this case are so unique and sort of extreme."

Prosecutors attempted to make the same case during the two-week trial, alleging Ms Crumbley ignored her son's pleas for help despite expressing concern about him in private messages.

They showed messages between Ms. Crumbley and a man she had an affair with in which she said - before attending the school meeting on the day of the shooting - that she was afraid her son would do "something dumb".

When she took the stand in her defense at her trial, Ms Crumbley sought to blame her husband for the gun purchased for their son.

She told jurors that her husband brought their son to a gun store the day after Thanksgiving to buy him a handgun as a gift.

She said she "didn't feel comfortable" being responsible for securing the gun and left James Crumbley to manage it.

Ethan Crumbley never took the stand, because he was expected to invoke his Fifth Amendment right against self-incrimination and refuse to testify.

Families of the victims have expressed frustration that school officials have not faced the same legal consequences as Mr and Ms Crumbley.

"Why isn't the system allowing the people to decide when it comes to the failures at the school?" Mr Myre told the BBC on Tuesday after the verdict.

"Is our government under a different set of rules?"

An independent investigation published last year alleged multiple failures from the school system, including allowing Ethan to return to class without checking his backpack.

The school district has pledged to review and improve its practices and policies in response to the report.

Noted