The mother of the Oxford High School shooter is asking a judge to dismiss her felony convictions because the prosecutor withheld cooperation agreements with two school officials who testified.

Jennifer Crumbley, along with her husband James Crumbley, was convicted of involuntary manslaughter, for providing the weapon used by their son in the mass shooting that left four students dead and six other students and a teacher injured.

But, attorney Michael Dezsi, in a motion filed Monday with the Oakland County Circuit Court, accused the prosecution of skirting the rules and ignoring tenets of criminal law.

“For as much talk as there has been about the charges in this case being unprecedented and the first of its kind in the country, this should come as no surprise given there is no legal basis to charge, convict, or sentence Mrs. Crumbley for the intentional crimes committed by her son,” he wrote. “This was a sham prosecution grounded in prosecutorial overreach.”

The filing makes a number of claims that Dezsi said denied his client a fair trial and justifies dismissing the convictions. At a minimum, he said, Crumbley deserves a new trial. It is expected James Crumbley’s legal counsel will file a similar request.                 A central argument is that prosecutors did not share cooperation agreements made with key witnesses against Crumbley.

Dezsi said the agreements were an incentive for school officials with an understanding that their cooperation could affect charging decisions.

“So clearly, those witnesses had a motive and a bias to testify in a way to shift responsibility away from the school and away from what they failed to do and to put that blame on the parents and onto Mrs. Crumbley, in particular,” he told Michigan Public Radio.

He said knowledge of those agreements with the school employees might have made a difference in the trial. But, Dezsi also said, the involuntary manslaughter charges should never have been filed in the first place after the shooter pleaded guilty to the murders as an adult. He said that should have absolved his client of criminal culpability.

“The prosecutor charged the shooter as an adult, sought to hold him accountable as an adult, and ultimately he was held accountable as an adult,” said Dezsi. “He was sentenced to life in prison without the possibility of parole.”

Chief Assistant Oakland County Prosecutor David Williams said that makes no difference.

“James and Jennifer Crumbley shouldn’t get off the hook because their son committed the worst crime possible,” he told Michigan Public Radio. “I’d argue that where their son committed an adult crime like a murder, that actually weighs more in favor of holding them accountable, not less. More than one person can be responsible for a crime.”

Williams said Crumbley’s defense counsel was not entitled to know about the agreements because school officials were never promised anything in exchange for their testimony. He said there was never any promise of immunity from prosecution.

The agreement is called a proffer and, more casually in legal jargon, a “queen for a day” deal. It typically promises that statements in court won’t be directly used against a witness. But it does not stop prosecutors from using the statements as the basis for follow-up investigations that could result in criminal charges.