Authorities from the Idaho State Police have unveiled images of a Ka-Bar knife sheath that was left by Bryan Kohberger at the University of Idaho crime scene. This crucial piece of evidence significantly contributed to his arrest amidst the extensive investigation into the tragic murders of four university students at an off-campus residence.

The release of these photos is part of a larger public records disclosure, which includes over 2,300 pages compiled by state investigators.

Additional evidence made public involves handwritten notes from investigators, images of victims’ nail clippings that underwent DNA testing, and samples from Kohberger’s Hyundai Elantra that were analyzed at the crime lab.

One of the evidence photos provided by the Idaho State Police depicts a Ka-Bar knife sheath, which is believed to have contained the weapon used in the horrific November 2022 killings of the four University of Idaho students. (Moscow Police Department)

Another evidence image from Idaho State Police shows the Ka-Bar knife sheath, thought to have housed the knife wielded by Bryan Kohberger in the fatal attack on the four students. (Moscow Police Department)

Forensic technicians tested the sheath for DNA evidence, ultimately recovering a sample on the snap.

The sample later turned into a tip developed by investigative genetic genealogists and ultimately led police to Kohberger’s parents’ home in Albrightsville, Pennsylvania, where he was arrested on Dec. 30, 2022.

An evidence photo supplied by Idaho State Police shows a pair of Radians-branded gloves retrieved from Bryan Kohberger’s parents’ home in Albrightsville, Pennsylvania. (Moscow Police Department)

He pleaded guilty in July and was sentenced to four consecutive prison terms of life without parole, plus another 10 years, for the murders of Madison Mogen, 21, Kaylee Goncalves, 21, Xana Kernodle, 20, and Ethan Chapin, 20.

Madison Mogen, top left, smiles on the shoulders of her best friend, Kaylee Goncalves, as they pose with Ethan Chapin, Xana Kernodle, and two other housemates in Goncalves’ final Instagram post, shared the day before the four students were stabbed to death. (@kayleegoncalves/Instagram)

According to the investigators’ notes, the victims left a sliding door open on the night of the attack for Goncalves’ dog, who was found unharmed in her bed. Goncalves and Mogen were both killed in Mogen’s bedroom.

Many of the records had to do with crime lab work, including DNA testing, fingerprint analysis and other measures early in the investigation.

This is a developing story. Check back with Fox News Digital for updates.