Oakland County Prosecutor Karen McDonald is under investigation by the Michigan Attorney Grievance Commission over allegations of ethical misconduct tied to her prosecution of the parents of the Oxford High School shooter, according to documents obtained by the Detroit Free Press.
The complaint alleges that McDonald crossed ethical boundaries during the cases against James and Jennifer Crumbley, fostering what it describes as a “must-win” approach and using the high-profile prosecutions in ways that raised concerns about professional conduct.
Prominent attorney files formal complaint
The grievance complaint was filed in August by Nancy J. Diehl, a veteran attorney with decades of prosecutorial experience. Diehl is a former president of the Michigan Bar Association, a former Judicial Tenure Commissioner, and a retired prosecutor who spent nearly 30 years with the Wayne County Prosecutor’s Office.
In the complaint, Diehl alleges that McDonald fostered a “must-win” environment during the Crumbley prosecutions and engaged in misconduct that included “withholding evidence from the defense — in this case, proffer agreements that protected two key witnesses who testified against the Crumbleys; using press conferences, media interviews and a public relations firm to allegedly prejudice the defendants early on; and giving a TV crew inside access to her office — while a gag order was in place — resulting in a Hulu documentary titled: ‘Sins of the Parents: The Crumbley Trials.’”
The filing challenges McDonald’s handling of what became the first successful prosecutions of parents whose child carried out a mass school shooting. James and Jennifer Crumbley were both convicted of involuntary manslaughter in connection with their son’s deadly 2021 attack at Oxford High School.
Historic prosecutions draw national attention
The prosecutions of James and Jennifer Crumbley drew national attention as precedent-setting cases that tested the boundaries of parental responsibility in mass shootings. Prosecutors argued the parents bore criminal responsibility for their son’s actions at Oxford High School, where four students were killed, and seven others were wounded in the November 2021 attack.
The cases were closely followed within Oakland County’s legal community and beyond, particularly by prosecutors, defense attorneys, and victims’ advocates watching how the unprecedented charges would fare in court.
The Crumbley prosecutions marked the first time in U.S. history that parents were convicted for a mass school shooting carried out by their child. Legal experts across the country monitored the trials as potential models for how similar cases could be pursued in the future amid ongoing concerns over gun violence and school safety.
James and Jennifer Crumbley were charged separately and tried in early 2024. Both were convicted of involuntary manslaughter and later sentenced to prison in connection with the shooting.
Grievance Commission investigation underway
The Michigan Attorney Grievance Commission is conducting a formal review of Karen McDonald’s conduct during the Crumbley prosecutions, a process that examines whether ethical rules governing attorneys were violated during the high-profile cases. The commission has the authority to investigate complaints of misconduct and, if warranted, recommend discipline ranging from a reprimand to the suspension or revocation of a law license.
Grievance complaints are filed regularly against attorneys, including prosecutors, particularly in contentious or closely watched cases. Most do not result in public discipline and are handled confidentially unless the commission determines further action is necessary.
In this instance, the allegations outlined in Nancy Diehl’s complaint have been described in publicly reported filings and include claims involving evidence disclosure, media activity during the prosecutions, and conduct while a court-imposed gag order was in effect. The grievance commission has not publicly commented on the scope or status of its review.
Political career implications
The grievance investigation comes as McDonald is seeking higher office, raising questions about how the high-profile Crumbley prosecutions intersected with her growing national profile. The cases drew widespread media attention and placed the Oakland County Prosecutor’s Office at the center of a national debate over accountability in school shootings.
McDonald’s office has pushed back strongly against the allegations. Jeff Wattrick, a spokesman for the Oakland County Prosecutor’s Office, said, “We are proud of that work and the verdicts in these cases.” He added that prosecutors routinely face complaints from defendants or attorneys unhappy with case outcomes, describing the grievance process as confidential unless the commission determines there is cause for concern.
“In this instance, we believe this is simply a political attack made with the same types of claims previously found not to have merit,” Wattrick said. “We continue to focus on the victims in the Oxford cases, and we stand by the jury’s verdict and the court’s rulings.”
McDonald, a Democrat, has served as Oakland County Prosecutor since 2021, after unseating longtime incumbent Jessica Cooper in the 2020 primary. She ran on a platform emphasizing criminal justice reform and transparency, and is now campaigning for Michigan attorney general as the grievance review moves forward.
Impact on Oakland County cases
The investigation has raised questions about whether it could spill into other cases handled by the Oakland County Prosecutor’s Office. While ethics reviews can invite added scrutiny from defense attorneys, they do not automatically affect active prosecutions.
The prosecutor’s office reviews thousands of law enforcement investigations each year, covering everything from misdemeanors to serious felony cases. Operations have continued as usual while the grievance review moves forward, with assistant prosecutors continuing to manage the county’s caseload under McDonald’s leadership.
What’s next
The Attorney Grievance Commission will continue its review under established procedures for evaluating allegations of attorney misconduct. The length of such investigations can vary, depending on the scope of the complaint and the evidence under review.
The commission’s review could result in the dismissal of the complaint or, if violations are substantiated, formal disciplinary action. No timeline has been announced, and the commission has not commented publicly on when a determination may be made.