Attorneys for Idaho quadruple murder suspect Brian Kohberger have filed papers indicating that they may use autism spectrum disorder as part of their defense.
Kohberger is accused of the stabbing of four University of Idaho students — Madison Mogen, Kaylee Goncalves, Xana Kernodle and Ethan Chapin — that took place in an off-campus home on Nov. 13, 2022. If convicted, Kohberger could face the death penalty.
Summaries of Ada County court documents show that his legal team has filed a motion titled “to Strike Death Penalty RE: Autism Spectrum Disorder,” although it is not certain how autism would be specifically used as a defense. It’s unclear whether Kohberger himself has ever been tested or diagnosed with autism, or if his lawyers were seeking a diagnosis.
The National Institute of Mental Health defines autism spectrum disorder as a neurological and developmental disorder that can affect how people interact with others, communicate, learn, and behave. The limited research available on a link between autism and crime rates has indicated that there is no convincing evidence to conclude that those on the autism spectrum are more likely to commit legal offenses than people without autism.
Meanwhile, prosecutors have requested Ada County Judge Steven Hippler to forbid opponents from presenting testimony on Kohberger’s neurological and psychiatric evaluation or from providing evidence that Kohberger hasn’t directly provided. Prosecuting attorney William Thompson Jr. has submitted a file citing an Idaho law which provides that “mental condition shall not be a defense to any charge of criminal conduct,” except for “expert evidence on the issues of any state of mind which is an element of the offense…”
The state of Idaho prohibits defendants from citing mental condition as a defense in criminal cases. “An attempt to suggest that autism-related symptoms would automatically constitute any kind of defense in a criminal case is probably destined to fail,” said Dave Leroy, a former Idaho attorney general.
This potential plea is the latest in a series of attempts by Kohberger’s lawyers to clear the possibility of the death penalty. In the past, they have cited America’s “ideological shift” and “evolving standards” concerning the death penalty. They also argue that Idaho’s execution methods — lethal injection and firing squad — are “cruel and unusual punishment,” and therefore in violation of the U.S. Constitution.
“It’s highly unlikely that the trial judge takes the death penalty off the table, but the defense is taking a kitchen sink approach, throwing everything on the table,” said Neama Rahmani, a former federal prosecutor and president of West Coast Trial Lawyers, in November 2024.
Kohberger’s trial is set to begin Aug. 11. Not guilty pleas have been entered on his behalf.
