Unsealed Brief: Why Prosecutors Planned to Call Amanda Kohberger in Bryan Kohberger Case

A recently unsealed trial brief explains why prosecutors intended to call a member of Bryan Kohberger’s family — in practice, his sister Amanda — as a witness during the criminal case arising from the killings of four University of Idaho students.

The Latah County prosecuting attorney told the court the State planned 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." Although the brief used the plural phrase "family members," the unsealed witness list identifies only Amanda Kohberger as an immediate-family witness the prosecution intended to call.

What prosecutors sought to establish

According to the brief, the family testimony was intended to establish background facts about Kohberger’s behavior and movements before he enrolled at Washington State University (Pullman) and during the roughly two weeks he spent at home in December 2022. The filing said the substance of the family witnesses’ testimony had been disclosed through reports of interviews with investigators.

Disputed and excluded material

Defense filings addressed what the parties would and would not present at trial. Defense attorney Anne Taylor noted that a more than decade-old incident from 2014 involving Kohberger and his sister — in which Kohberger reportedly gave his sister’s cell phone to a mall kiosk in exchange for money — would not be introduced at trial. The parties agreed in a sealed stipulation to exclude that matter; the incident previously led to a minor theft charge that was later expunged.

Family involvement and procedural notes

Court records and reporting have described Kohberger’s parents’ actions around the time of the killings: his father, Michael, traveled to accompany Bryan for part of the December 2022 drive back to Pennsylvania, and his mother, MaryAnn, spoke with him at length on the day of the murders. The filings note that Idaho recognizes a limited parent-child testimonial privilege in some circumstances — generally when the child is a minor and the proceeding is noncriminal — a rule that does not broadly prohibit parents from testifying in adult criminal cases.

Kohberger had listed his parents, two sisters and an uncle as potential mitigation witnesses for the penalty phase of proceedings. Ultimately, none of those relatives testified at trial: Kohberger pleaded guilty in July to the killings of Madison Mogen, Kaylee Goncalves, Xana Kernodle and Ethan Chapin, and is serving four life sentences without the possibility of parole. Authorities have not publicly confirmed a motive.

Note: This summary is based on filings that were previously under seal and subsequently unsealed; it focuses on what prosecutors said they planned to prove with family testimony and what the defense agreed to exclude.