The mother of a US school shooter has been convicted of manslaughter in a landmark trial

A US jury found a Michigan mother guilty of four counts of involuntary manslaughter over a school shooting carried out by her teenage son.

Jennifer Crumbley testified in her own defence, saying her husband was responsible for securely storing firearms in the family home. Source: Getty / Jeff Kowalsky

A Michigan jury on Wednesday convicted the mother of a teenager who fatally shot four classmates at a high school near Detroit of manslaughter after prosecutors argued she bore responsibility because she and her husband gave their son a gun and ignored warning signs of violence.

The trial of Jennifer Crumbley, 45, was believed to be the first in which a parent faced a manslaughter charge in the United States stemming from a school shooting by their child. She faced four counts of involuntary manslaughter, one for each of the victims at Oxford High School in the 2021 shootings.

Her husband, James Crumbley, 47, is set to face his own trial on manslaughter charges in March.

Jennifer Crumbley and her husband James bought a gun just days before the shooting at Oxford High School which left four students dead. Credit: Oakland County Sheriff

The couple's son, Ethan, was 15 at the time of the shooting at Oxford High School involving a semi-automatic handgun. He pleaded guilty in 2022 to four counts of first-degree murder and other charges and was sentenced to life in prison without parole in December.

The United States, a country with persistent gun violence, has experienced a series of school shootings over the years, often carried out by current or former students.

Oakland County prosecutors argued during the trial that Jennifer Crumbley, even though she did not pull the trigger, stored the gun and ammunition in a negligent manner and should be held criminally responsible for the deaths. They said she and her husband knew Ethan was mentally in a "downward spiral" and posed a danger to others but allowed him access to firearms, including the 9mm pistol that was purchased as his Christmas present and was used to kill his classmates.

Ethan Crumbley was 15 at the time of the shooting at Oxford High School. He pleaded guilty in 2022 to four counts of first-degree murder and other charges and was sentenced to life in prison without parole last year. Credit: Oakland County Sheriff's Office

Shannon Smith, the attorney for Jennifer Crumbley, argued that she was not responsible for buying or storing the gun used by her son in the shootings, that there were no real warning signs that he would kill his classmates and that she could not have reasonably foreseen that the crime would take place.

Jennifer Crumbley testified in her own defence, saying her husband was responsible for securely storing firearms in the family home and that while her son had been anxious about getting into college and what he would do with his life, she did not think his problems merited seeing a psychiatrist.