Idaho Murders Update: 'Most Important' Evidence' Puts Kohberger 'In The Bed' Of Crime

A former FBI official has identified the knife sheath DNA evidence in the Idaho murders case as the "most important" evidence so far against the quadruple killings suspect Bryan Kohberger.

"The DNA puts him not just in the house but, literally, in the bed where two victims were found," Former FBI Deputy Director Andrew McCabe told CNN. "It's absolutely the most critical piece of evidence."

The ex-FBI official was pertaining to the DNA profile obtained from the knife sheath found at the crime scene, which later matched a DNA profile obtained from the trash outside Kohberger's house in Albrightsville, Pennsylvania, according to a probable cause affidavit released earlier.

"It's possible that that DNA got placed on the button of the knife sheath before the homicide. Maybe as he was picking up his things and preparing to go that night before he put his gloves on. So, again, it gives you that piece of DNA that you might not have otherwise collected from the crime scene if he was smart enough to wear gloves during the commission of the crime," McCabe said.

In the affidavit released after Kohberger's first appearance in court on Jan. 5, Moscow police officer Brett Payne shared that he discovered the knife sheath on the bed next to the dead body of one of the victims on the third floor of the King Road apartment.

The object had been reportedly stamped with "Ka-Bar," "USMC" and the U.S. Marine Corps eagle globe and anchor insignia on the outside, Payne said in the affidavit. The Idaho State Lab later located a single source of male DNA profile on the button snap of the knife sheath.

Meanwhile, Paul Mauro, a former New York Police Department inspector, wrote through Fox News that the knife sheath evidence is currently the only direct and not circumstantial evidence in the case.

"In the absence of the knife itself, having a sheath that matches to the same knife that caused the wounds (a fact which will need to be demonstrated), found literally beside the body of one of the victims, is going to be tough to refute," Mauro said.

Other evidence stated in the affidavit included surveillance videos, cellphone records and license-plate readers that tracked the suspect's white Hyundai Elantra to narrow down Kohberger as the suspect.

Kohberger is currently being held without bail in Latah County Jail in Idaho as he faces four first-degree murder charges and felony burglary in relation to the fatal stabbings of Kaylee Goncalves, 21, Madison Mogen, 21, Xana Kernodle, 20, and Ethan Chapin, 20.