New court filings in the Idaho student murders case could severely handicap suspect Bryan Kohberger’s defense, according to legal experts – he allegedly purchased a Ka-Bar knife on Amazon months before the murders and then shopped for a replacement days after they took place.

Bryan Kohberger, a 30-year-old former criminology Ph.D. student, is accused of using a large, bladed weapon to kill four University of Idaho undergrads – Madison Mogen, 21, Kaylee Goncalves, 21, Xana Kernodle, 20 and Ethan Chapin, 20.

According to Latah County Coroner Cathy Mabbutt, all four victims died with multiple stab wounds. At least two of them were so intoxicated at the time of the attack that they were unable to resist at all, prosecutors wrote in court filings. 

Under Mogen’s body, police found a Ka-Bar knife sheath, stamped with a United States Marine Corps logo and allegedly containing Kohberger’s DNA on the snap.

While search warrants show police recovered knives after Kohberger’s arrest, none have been publicly identified as a potential murder weapon. 

Kohberger’s trial is scheduled to begin Aug. 11 in Boise.

He could face the death penalty if convicted. A judge entered not-guilty pleas on his behalf at his arraignment in May 2023.