James Crumbley, the father of a 15-year-old who shot and killed four students at Oxford High School in Michigan in 2021, was convicted of involuntary manslaughter by an Oakland County jury on Thursday. 

Crumbley and his wife Jennifer, who was also found guilty of involuntary manslaughter last month, are the first parents to be convicted for a mass shooting carried out by their child, with their verdicts triggering debate about the culpability of parents in crimes committed by their children. Each could face sentences up to 15 years in prison.

“It’s very rare for parents to be held accountable when their children have access to firearms and do harm,” Adam Winkler, a law professor at the University of California, Los Angeles, and the author of Gunfight: The Battle Over the Right to Bear Arms in America, tells TIME. 

Winkler describes Thursday’s verdict as “not unexpected but still surprising,” adding that the facts in Crumbley’s case were “unusually” clear. “This case may not set a huge precedent,” he says, “because there won’t be as many cases where the facts are as egregious as this one.”

Michigan School Shooter’s Mother Jennifer Crumbley Found Guilty of Manslaughter

James and Jennifer Crumbley had bought their son Ethan the pistol that the teen used in the November 2021 shooting that killed four students and injured seven. Ethan pleaded guilty in 2022 to numerous charges, including four counts of first-degree murder, and is serving a life sentence without parole.

In their separate trials, prosecutors argued that the Crumbleys had ignored warning signs about their son’s mental health and had been negligent in allowing their son to have a gun.

Prosecutors pointed to a journal entry Ethan had written: “I have zero HELP for my mental problems and it’s causing me to SHOOT UP THE F—ING SCHOOL … I want help but my parents don’t listen to me so I can’t get any help.”

On the morning of the shooting, James and Jennifer Crumbley attended an urgent school meeting after Ethan’s teacher found drawings he had made of a gun and bloody figures, but they declined to take him home. When the teen began his rampage hours later, James, who was working as a DoorDash driver, rushed home to look for the gun.

James’ defense lawyer argued that there was no evidence that the 47-year-old had declined to help Ethan and that “James had no idea that his son was having a hard time.”

In a statement sent to media outlets, attorney Ven Johnson, who represents the victims’ families, said that the verdicts of the Crumbleys “won’t bring back the lives of these four students, but it represents one more step towards holding everyone responsible accountable under the law, which is justice for the victims’ families and the Oxford community.”

While it remains to be seen if the manslaughter convictions will be overturned in the coming years—experts say appeals are expected for the cases due to their unprecedented nature—the Crumbley verdicts mark a major milestone in the longstanding debate over the responsibility of parents in preventing school shooters. There have been more than 1,500 school shootings in the U.S. since 1997, according to the American Academy of Pediatrics and Education Week.

“It’s shown a new avenue, a different sort of treatment towards school shootings and accountability that hasn’t yet been seen,” Tim Carey, law and policy advisor at the John Hopkins Center for Gun Violence Solutions said on a podcast after Jennifer’s verdict.

Legal experts, however, are divided on whether the recent verdicts can effectively tackle gun violence in the future. Stephen J. Morse, a professor of law and psychiatry at the University of Pennsylvania, told the BBC after Jennifer’s verdict last month that it could result in courts looking for “scapegoats” in similar cases. “I understand that she was not necessarily the best mother in the world, but this is not a crime,” he said.

Read More: The Problem With Punishing Parents for Their Kids’ Crimes

Meanwhile, Winkler says that he does not think the verdicts of the Crumbleys will have much of an effect on gun policy in the U.S., but they could have an impact on gun violence. “Gun control politics are such that it’s going to take much more than individual cases to change the direction of gun control today,” says Winkler, though he notes that even without any future legislation clarifying liability, the recent convictions could still influence individual behavior and attitudes around guns. 

“It could lead to more prosecutors bringing charges against parents when their children use firearms. And that could have a similar effect of gun control,” he says. “It would encourage more parents to keep guns out of the hands of their children, to take safe storage more seriously, in which case it doesn’t change the law on gun control but maybe changes how people at home control their guns.”