PONTIAC, Mich. (AP) — The parents of a Michigan school shooter were each sentenced to at least 10 years in prison Tuesday for failing to take steps that could have prevented the killing of four students in 2021.

Jennifer and James Crumbley are the first parents convicted in a U.S. mass school shooting. They were found guilty of involuntary manslaughter after prosecutors presented evidence of an unsecured gun at home and indifference toward the teen’s mental health.

Ethan Crumbley drew dark images of a gun, a bullet and a wounded man on a math assignment, accompanied by despondent phrases. Staff at Oxford High School did not demand that he go home but were surprised when the Crumbleys didn’t volunteer it during a brief meeting.

Later that day, on Nov. 30, 2021, the 15-year-old pulled a handgun from his backpack and began shooting at the school. Ethan, now 17, is serving a life sentence for murder and other crimes.

Before sentencing, family members of the students killed in the shooting asked a judge to sentence the parents to 10 years, condemning them as failures whose selfishness led to four deaths and a community tragedy.

“The blood of our children is on your hands, too,” said Craig Shilling, wearing a hoodie with the image of son Justin Shilling on his chest.

Nicole Beausoleil, the mother of Madisyn Baldwin, recalled simple things she enjoyed doing for her daughter, such as scheduling an oil change for her car or helping choose senior year classes.

“While you were purchasing a gun for your son and leaving it unlocked, I was helping her finish her college essays,” Beausoleil told James and Jennifer Crumbley.

Five deputies in the courtroom stood watch over the Crumbleys and more lined the walls. They are the first parents convicted in a U.S. mass school shooting.

Prosecutors said “tragically simple actions” by both parents could have stopped the catastrophe.

The couple had separate trials in Oakland County court, 40 miles (64 kilometers) north of Detroit. Jurors heard how the teen had drawn a gun, a bullet and a gunshot victim on a math assignment, accompanied by grim phrases: “The thoughts won’t stop. Help me. My life is useless. Blood everywhere.”

Ethan told a counselor he was sad — a grandmother had died and his only friend suddenly had moved away — but said the drawing only reflected his interest in creating video games.

The Crumbleys attended a meeting at the school that lasted less than 15 minutes. They did not mention that the gun resembled one James Crumbley, 47, had purchased just four days earlier — a Sig Sauer 9 mm that Ethan had described on social media as his “beauty.”

His parents declined to take him home, choosing instead to return to work and accepting a list of mental health providers. School staff said Ethan could stay on campus. A counselor, Shawn Hopkins, said he believed it would be safer for the boy than possibly being alone at home.

No one, however, checked Ethan’s backpack. He pulled the gun out later that day and killed four students — Tate Myre, Hana St. Juliana, Shilling and Baldwin — and wounded seven other people.

There was no trial testimony from specialists about Ethan’s state of mind. But the judge, over defense objections, allowed the jury to see excerpts from his journal.

“I have zero help for my mental problems and it’s causing me to shoot up the … school,” he wrote. “I want help but my parents don’t listen to me so I can’t get any help.”

Asked about Ethan reporting hallucinations months before the shooting, Jennifer Crumbley, 46, told jurors he was simply “messing around.”

At the close of James Crumbley’s trial, the prosecutor demonstrated how a cable lock, found in a package at home, could have secured the gun.

“Ten seconds,” McDonald said, “of the easiest, simplest thing.”