Bryan Kohberger would have come face-to-face with his own sister in court if his murder case had gone to trial.
It was previously revealed that Amanda Kohberger was on the prosecution’s witness list, and a newly unsealed court document now sheds more light on what her testimony might have covered.
Latah County Prosecuting Attorney Bill Thompson outlined the state’s case in a trial brief that had been filed under seal.
“The State intends to call family members of Defendant for the purpose of establishing certain facts before Defendant moved to Pullman in late summer 2022, as well as facts about Defendant’s conduct when he returned home to Pennsylvania in December 2022,” Thompson wrote.
He added: “The nature of this testimony has been disclosed through reports of interviews.”
Although Thompson referenced “family members,” the witness list he filed around the same time — now also unsealed — includes only one immediate family member: Bryan’s sister Amanda.
In her own trial brief, defense attorney Anne Taylor wrote that prosecutors would not be permitted to present at trial an incident involving Kohberger and his sister from a decade earlier, when he was allegedly struggling with drug addiction.
Taylor said that a 2014 incident, which “involved Mr. Kohberger’s taking his sisters cellular phone to a kiosk at a mall in exchange for money,” would not be introduced at trial. Both sides agreed to this in a “sealed stipulation.”
The brief further explained: “His father called police, the end result of which was a minor theft charge that was later expunged.”
It remains unclear why prosecutors listed only Amanda and not other family members, including Kohberger’s parents.
Kohberger’s father, Michael, flew across the country to join his son as he drove from Washington State University back to Pennsylvania in December 2022 — at a time when, unbeknownst to him, investigators were closing in on Bryan as a suspect.
His mother, MaryAnn, spoke with him shortly after the murders, including during a call while he drove back to the crime scene just hours after four University of Idaho students were fatally stabbed.
Kohberger reportedly spent more than three hours on the phone with his mother on the day of the killings.
Idaho law generally protects parents from being compelled to testify against their children, but that protection applies only when the child is a minor and the case is a non-criminal proceeding.
In court filings, Kohberger listed his parents, his two sisters and his uncle Randall as potential mitigation witnesses for the penalty phase of his trial.
Ultimately, none of his family members were called to testify for or against him. Kohberger pleaded guilty in July to murdering Madison Mogen, Kaylee Goncalves, Xana Kernodle and Ethan Chapin at their off-campus home near the University of Idaho.
He is now serving four life sentences without the possibility of parole.
A motive has not been publicly established.
