Prosecutors said they intended to seek the death penalty if Kohberger is convicted at his trial, which is set to begin in August.
But his attorneys asked Judge Steven Hippler to remove the death penalty as a possible punishment, citing Kohberger’s diagnosis of autism spectrum disorder. They have also filed several other motions challenging the death penalty, including one based on purported violations by the state in providing evidence.
“Mr. Kohberger’s autism spectrum disorder (ASD) reduces his culpability, negates the retributive and deterrent purposes of capital punishment, and exposes him to the unacceptable risk that he will be wrongfully convicted and sentenced to death,” defense attorneys wrote in court papers.
They argued that executing someone with autism would constitute cruel and unusual punishment under the Eighth Amendment to the U.S. Constitution.
Prosecutors argued that under U.S. Supreme Court precedent, the only mental disability that precludes imposition of the death penalty is an intellectual disability — and Kohberger’s diagnosis was of mild autism “without accompanying intellectual . . . impairment.”
Kohberger was a criminal justice graduate student at Washington State University, in Pullman, about 10 miles (16.1 kilometers) from Moscow, at the time of the killings in November 2022. He was arrested in Pennsylvania weeks later. Investigators said they matched his DNA to genetic material recovered from a knife sheath found at the crime scene.
Autopsies showed the four were all likely asleep when they were attacked, some had defensive wounds and each was stabbed multiple times.