Bryan Kohberger Prosecutors Explain Reason for Having Murderer's Family Testify at Trial

A recently unsealed trial document provides insight into why prosecutors intended to call a family member of Bryan Kohberger to testify during his trial. The testimony was meant to outline certain events involving Kohberger before he attended Washington State University and during the two weeks he spent at home prior to his arrest.

Although the brief mentions "family members," the states witness list included only Amanda Kohberger, his sister.

Had the case gone to trial, Bryan Kohberger would have faced his own sister in court. The unsealed court document clarifies that Amanda Kohberger was expected to provide testimony detailing Kohberger's actions and whereabouts in late summer 2022 before moving to Pullman, as well as his conduct when he returned home to Pennsylvania in December 2022.

Latah County Prosecuting Attorney Bill Thompson stated in the trial brief: 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 Defendants conduct when he returned home to Pennsylvania in December 2022. The nature of this testimony has been disclosed through reports of interviews.

Although Thompson referred to "family members," the witness list filed at the same time included only Amanda Kohberger. Defense attorney Anne Taylor noted that prosecutors would not introduce an incident from 2014 involving Kohberger and Amanda during his alleged period of drug addiction. In that incident, Kohberger reportedly took his sisters cell phone to a mall kiosk in exchange for money. The resulting minor theft charge was later expunged, and both sides agreed not to present this information at trial.

It remains unclear why Amanda was the only family member on the witness list, as Kohberger's parents were not included. In December 2022, his father, Michael Kohberger, accompanied him on a drive back to Pennsylvania from Washington State University, unaware that police were tracking his son. His mother, MaryAnn Kohberger, spoke with him for several hours immediately following the murders, which involved four University of Idaho students.

Kohberger spent over three hours on the phone with his mother on the day of the killings. Idaho law generally does not compel parents to testify against their children if the child is a minor and the proceeding is non-criminal.

For the penalty phase of the trial, Kohberger had listed his parents, two sisters, and his uncle as potential mitigation witnesses. Ultimately, none of these family members testified, as he pled guilty in July to the murders of Madison Mogen, Kaylee Goncalves, Xana Kernodle, and Ethan Chapin. Kohberger is currently serving four life sentences without the possibility of parole.

Author's Analysis: The Role of Family Testimony in the Kohberger Case

The recently unsealed trial documents reveal why prosecutors initially planned to call Amanda Kohberger, Bryan Kohberger’s sister, as a witness. Her testimony was intended to provide a timeline of Kohberger’s movements and behavior before and after his time at Washington State University, focusing specifically on late summer 2022 and December 2022.

Although the trial brief referenced "family members," the official witness list included only Amanda. The documents clarify that she was expected to describe Kohberger’s conduct during these periods, shedding light on his actions prior to his arrest. Prosecutors and defense counsel agreed to exclude a minor 2014 incident involving Amanda, avoiding any introduction of unrelated past events.

Notably, Kohberger’s parents were not on the witness list, despite being present during key moments, such as the drive back to Pennsylvania and phone conversations following the murders. This omission aligns with legal norms, as Idaho law generally does not compel parents to testify against an adult child in non-criminal proceedings.

In the end, none of Kohberger’s family testified. His guilty plea in July rendered their potential testimony unnecessary, and he is now serving four life sentences without parole. The documents provide context for the prosecutors’ strategy, illustrating the balance between evidentiary value and legal constraints in high-profile criminal cases.

Sources:

• Bryan Kohberger Prosecutors Reveal Why They Planned to Have Murderer's Family Testify Against Him at Trial