Jennifer Crumbley’s Conviction Offers New Legal Tactic in Mass Shooting Cases

The guilty verdict on Tuesday against the mother of a Michigan teenager who murdered four students in 2021 in the state’s deadliest school shooting is likely to ripple across the country’s legal landscape as prosecutors find themselves weighing a new way to seek justice in mass shootings.

But, legal experts say, don’t expect a rush of similar cases.

“I have heard many people say they think a guilty verdict in this case will open the floodgates to these kinds of prosecutions going forward,” said Eve Brensike Primus, a law professor at the University of Michigan. “To be honest, I’m not convinced that’s true.”

That’s because prosecutors in Michigan had notably compelling evidence against the mother, Jennifer Crumbley — including text messages and the accounts of a meeting with school officials just hours before the shooting at Oxford High School on Nov. 30, 2021 — that jurors felt proved she should have known the mental state of her son, Ethan Crumbley, who was 15 at the time.

Ethan pleaded guilty in 2022 and was sentenced to life in prison without the possibility of parole. Ms. Crumbley was convicted on four counts of involuntary manslaughter, one for each student her son killed. She faces a maximum penalty of 15 years in prison, and sentencing is scheduled for April 9.

Ms. Crumbley’s husband, James Crumbley, 47, will be tried separately in March.

“Could more prosecutors file charges emboldened by this kind of ruling and the verdict?” Professor Primus said. “Sure. Do I think they will be successful around the country getting charges to stick if they don’t have the requisite facts that can demonstrate real knowledge? No.”

Still, Professor Primus and other legal experts who have followed the case say the successful prosecution of Ms. Crumbley, 45, provides a template for prosecutors around the country to pursue similar cases.

“I think, in many ways, this case will certainly make prosecutors look at their work a little differently when it comes to parents who are neglectful, in terms of how they handle weapons around the home, making weapons available for their kids,” said George Gascón, the district attorney of Los Angeles.

The issue of parental responsibility for the crimes of children is one Mr. Gascón has considered before, with a recent case involving a minor charged with vehicular manslaughter.

“I felt very strongly about going after the father,” he said. “Eventually I was advised against it and we didn’t. It would have been very novel. I thought there was a lot of parental responsibility there.”

In the aftermath of mass shootings by teenagers and young adults, scrutiny often falls on the parents, as much to weigh the specific circumstances of the crime as to learn something that could prevent that next shooting somewhere in America.

“The discussion has been, what can we do about this?” said Lewis Langham Jr., emeritus professor at Cooley Law School in Lansing, Mich. “The parents should have done something. But it’s never gotten to the point where the parents were actually charged, and now convicted, at least one of the parents here in Michigan. That’s the uniqueness about the case.”

Experts anticipate that prosecutors around the country will consider similar charges in mass shootings. But some said they also worried that the tactic could be applied to many other circumstances, and in the process deepen racial disparities in the criminal justice system.

Evan Bernick, a law professor at Northern Illinois University, said the Crumbley case was a “horrifying” one. But he added: “No one who is serious about scaling back mass incarceration should be celebrating any expansion of criminal liability, much less one that makes it easier for prosecutors to put parents in prison for the crimes of their children.”

He pointed to past examples where policing parents resulted in racial inequities, like with truancy laws, which allowed prosecutors to go after parents for their children’s school absences. He now worries about higher stakes in the wake of the Crumbley case.

“If we have children who are at risk of gang activity and their parents just didn’t see the signs and something terrible happens, I don’t think that we can trust prosecutorial restraints to hold the line on this just to situations as horrific as this one,” Mr. Bernick said.

Legal experts also say they worry the case will become a way for prosecutors to force plea deals from parents, far from the national spotlight that the Crumbley case had.

“Having this tool as a way of threatening or warning or coercing or pushing parents to accept plea bargains — like so much of the criminal law, I’m afraid that it’s going to consume lives quite out of sight,” said Ekow Yankah, a law professor at the University of Michigan.

He added that the Crumbley case upended one of the most basic principles of criminal law that he teaches to his first-year students: “You are not responsible for the actions of another.”

The trial, its implications for the law and where the jury would land, consumed conversations among Mr. Yankah’s fellow law professors in recent weeks.

“To be honest, we were all over the place,” he said. “Some people thought yes, some people thought no. Intellectually I thought it could go either way. But I will admit, even though I say that, when I saw that she actually got a guilty verdict, the first word out of my mouth was, ‘Whoa.’”