Crumbley parents' case: Judge denies motion to include testimony on 'pathway to violence'

A judge overseeing the trial of the parents of the Oxford High School shooter has denied a motion by prosecutors seeking to admit as evidence testimony from two experts on mass shootings.

Jennifer and James Crumbley, parents of Ethan Crumbley, each are charged with involuntary manslaughter for their alleged roles in the killings of four Oxford students in the shooting: Madisyn Baldwin, Tate Myre, Hana St. Juliana and Justin Shilling.

Their son, Ethan Crumbley, on Oct. 24 pleaded guilty to 24 criminal charges related to the Nov. 30 rampage that left four students dead and injured seven other people. He told a judge he obtained the weapon by giving his father the money to buy the gun and that it wasn't locked the day of the shooting.

Oakland County Prosecutor Karen McDonald previously argued in court filings that there was a “pathway to violence” provided to the shooter by his parents’ behavior and that the parents exhibited gross negligence by allowing their son access to a gun. Attorneys for the parents have contended the gun was secured before the teen obtained access to it.

Prosecutors in the parents' case sought to include expert testimony related to the "pathway to violence," while defense attorneys argued that the testimony was not relevant and should not be allowed. Judge Cheryl Matthews denied the prosecutors' request, writing in a 16-page filing dated Nov. 18 that it should be excluded largely due to a "lack of relevance."

The two prosecution witnesses, Dr. Jillian Peterson and Dr. Dewey Cornell, testified at an Oct. 28 hearing that perpetrators of mass violence exhibit noticeable changes that people around them cannot ignore, and that the escalation to acts of violence can be prevented.

Peterson is an associate professor of criminology and criminal justice and director of the Forensic Psychology Program at Hamline University, as well as the co-president of a nonprofit, nonpartisan research center that aims to use data and analysis to implement policies that reduce violence. Cornell is a University of Virginia forensic psychologist whose research has focused on youth violence, school violence and threat assessment.

Their testimony was based on research suggesting that mass shooters plan and prepare before carrying out acts of violence and do not "just snap." They testified that mass shooters often "leak" their plans to others, providing opportunities for intervention.

Peterson testified about findings from her research that suggest such pathways stem from early childhood trauma and slowly build to a crisis point. Something then pushes the individual over the edge, prompting changes that people around them notice. In a cry for help, they tend to leak their plans to commit a harmful act, she testified.

Meanwhile, Cornell testified "that it is profoundly evident that mass shootings can be prevented and shooters don't 'just snap,'" according to background included in Matthews' opinion.

However, Matthews pointed to Peterson's own admissions about knowledge and data limitations in reviewing the case and evidence.

"Importantly, she admitted that she did not know if the Defendants saw the shooter's notebooks, or his journal," Matthews wrote. "She further acknowledged that she didn't know if the Defendants were aware of the text messages that the shooter sent to his friend. She testified that her initial impression of this school shooting was based upon news reports, and that news reports don't always accurately report the facts."

Matthews lauded Peterson's and Cornell's research endeavors, but ultimately found that it should be excluded, further noting that "there is no evidence that any expert in mass shootings has been qualified by a court to opine on the pathway to violence in criminal proceedings similar to this case."

"Last, and most paramount to this conclusion is the fact that the experts admitted that they cannot predict what actions or inactions would stop a school shooting," she wrote.

She wrote that it would be "confusing and misleading" to present the pathway to violence theory to jurors "when the experts cannot say with any certainty whether any action or inaction by the Defendants in this case would have changed the outcome."

The parents are slated to stand trial in early 2023.

jgrzelewski@detroitnews.com

Twitter: @JGrzelewski