(CNN) — James and Jennifer Crumbley, the parents of the teenager who killed four students in the 2021 school shooting in Oxford, Michigan, are set to be sentenced to prison on Tuesday, weeks after being convicted of manslaughter.

They each face up to 15 years in prison. The two have already been imprisoned for over two years since their arrest in a Detroit warehouse days after the shooting. Though the parents were tried separately, their sentencing will take place together in an Oakland County courtroom.

In separate sentencing memos, prosecutors asked the judge to sentence each parent to 10 to 15 years in state prison, saying the parents showed a “chilling lack of remorse.” In particular, the prosecution noted James Crumbley made threats against Prosecuting Attorney Karen McDonald in several jail calls. “There will be retribution, believe me,” he said in one, according to the memo.

But attorneys for the parents have asked for their clients to be sentenced to less than five years in prison each. In a sentencing memo dated April 5, the defense attorney for Jennifer Crumbley asked the judge to give her client credit for the 27 months she has served behind bars and allow her to be placed under house arrest “on a tether” at the defense attorney’s home, where she can be supervised.

That way, “Mrs. Crumbley would be able to work remotely and begin to rebuild her life,” but would not be out in the community, the memo says. The memo notes Jennifer Crumbley is “hugely distraught and remorseful” about the shooting and said a sentence between 29 to 57 months would be “more proportional” than what prosecutors are asking for.

In a separate memo from April 5, James Crumbley’s defense attorney said his client has “expressed significant remorse” and sorrow for those affected by the killings, and asked the judge to sentence him either to 28 months in prison with credit for time served, along with a maximum period of supervision, or 43 months in prison with credit for time served.

The defense also denied that James Crumbley has threatened physical harm to the prosecuting attorney, saying he “at worst engaged in frustrated name calling.”

Prior to the sentence, the victims and their families will have the opportunity to speak about the impact of the shooting.

The sentencing represents the end of a dramatic saga that has pushed the boundaries of who is responsible for a mass shooting. Prosecutors used a novel legal theory in charging the parents with manslaughter even though they did not pull the trigger — the first time the parents of a school shooter have been charged with such serious crimes.

Ethan Crumbley, 15 at the time, brought a Sig Sauer 9mm firearm from home and opened fire at Oxford High School on November 30, 2021, killing four students and wounding six others and a teacher.

His parents were arrested days afterward and accused of involuntary manslaughter for their role in the killings.

What happened at the trials

At their trials, prosecutors used testimony from shooting survivors, police investigators and school employees to prove that the parents were “grossly negligent” in allowing their teenage son to have access to the gun and ignoring signs of his spiraling mental health.

In particular, the testimony showed James purchased the firearm for his son on Black Friday, four days before the shooting. The next day, Jennifer took her son to the firing range for target practice. “Mom & son day testing out his new Xmas present,” she wrote afterward on social media. The parents failed to properly secure the firearm, as James Crumbley hid it in their bedroom but did not use any locking device, the prosecution argued.

In addition, the trials focused on a pivotal meeting between school employees, Ethan and his parents on the morning of the shooting. Ethan had been called into the school office after he made disturbing writings on a math worksheet, including the phrases “blood everywhere” and “my life is useless” and drawings of a gun and bullet.

The school employees recommended the parents immediately take him out of class and get him mental health treatment, but they declined to do so, saying they had work. The Crumbleys also did not mention to the school the recent gun purchase. Afterward, Ethan was sent back to class. About two hours later, he took the gun out of his backpack and opened fire at the school.

Jennifer Crumbley took the stand in her trial and blamed her husband, the school and her son for the shooting, while expressing no regret of her own. “I’ve asked myself if I would have done anything differently, and I wouldn’t have,” she testified.

By contrast, James Crumbley did not testify in his trial, and his attorney argued he simply didn’t know about his son’s plans or mental issues.

Still, Jennifer Crumbley was convicted of four counts of involuntary manslaughter in early February, and James Crumbley was convicted of the same counts in March.

In pre-sentence investigation reports included in the prosecution’s sentencing memos, the parents continued to defend their actions.

“I am wrongly accused, and now wrongly convicted of Involuntary Manslaughter. My actions were that of any other parent,” James Crumbley wrote. He also said he “had no knowledge of what (my son) was going to do, or presented with ANY warning signs,” and he defended his gun safety efforts. “I followed the law and took gun safety to the point as needed.”

In her report, Jennifer Crumbley sought to clarify her testimony, saying she would not have done anything differently. “With the information I have now, of course my answer would be hugely different. There are so many things that I would change if I could go back in time,” she said. “I never imagined he would hurt other people in the way that he did.”

The parents’ defense attorneys have argued the charges have no legal justification, but appeals courts have upheld them.

Ethan was sentenced last year to life in prison without parole after pleading guilty to terrorism causing death, four counts of murder and 19 other related charges. He did not testify his parents’ trials, as his attorneys said he would invoke his Fifth Amendment right to silence.

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