The DNA found at the scene of the gruesome University of Idaho murders is 5.37 octillion times more likely to belong to prime suspect Bryan Kohberger than to a member of the public, authorities say.
Kohberger, 28, is charged with four counts of first-degree murder and burglary in connection with the stabbing in Moscow, Idaho, on Nov. 13, 2022.
An innocent pleaded on his behalf last month when the suspect chose to “keep quiet.” Prosecutors have not said whether they will seek the death penalty.
The bodies of Madison Mogen, Kaylee Goncalves, Xana Kernodle and Ethan Chapin were found in a rental home across the street from the University of Idaho campus.
The murders shocked the rural community of Idaho and neighboring Pullman, Washington, where Kohberger was a graduate student studying criminology at Washington State University.
The documents also reveal the strategy used to identify Kohberger as the prime suspect in the case.
Bryan Kohberger’s DNA is a ‘statistical match’ to DNA found on a knife sheath at the scene of the November University of Idaho murders
The bodies of Kaylee Goncalves, Madison Mogen, on Kaylee’s shoulders, Ethan Chapin and Xana Kemodle were found in a rental home across the street from the University of Idaho campus
A Ka-Bar knife, similar to the one believed to have been used in the murders, DNA from the sheath was found at the scene
When DNA is found at the crime scene that does not belong to the victims, the first thing the police do is run it through their own database to check if it matches the DNA of previous perpetrators.
This process is called a short tandem repeat comparison (STR) and tests the sample against 20 DNA markers — enough to identify the person if their own DNA is already in the system, or, in some cases, if an immediate family member’s DNA is in the system. the system (for example, a parent or sibling).
A criminal affidavit filed last January, shortly after Kohberger was arrested, says DNA matching that of the suspect was found on a knife scabbard recovered from the crime scene, close to the bodies of Mogen and Goncalves.
Investigators later closely matched the DNA on the sheath with DNA found in trash taken from Kohberger’s parents’ home in Pennsylvania, where he was arrested in December 2022.
‘A traditional STR DNA comparison has been made between the STR profile found on the Ka-Bar knife sheath and the DNA of the suspect. The comparison showed statistical agreement,” the new filing read.
“The odds of seeing the STR profile are at least 5.37 octillion times greater when the suspect is the source than when an unrelated person randomly selected from the general population is the source.”
The documents also say the scabbard was found “partially under Madison’s body and the comforter on the bed.”
On December 27, a police undercover team seized trash from the Kohberger family home in Albrightsville, Pennsylvania, helping to formalize the DNA profile.
The home of the murder scene is located on King Road in Moscow, a quiet cul-de-sac near the University of Idaho campus
Before these documents were made public, officials released few details about how they identified Kohberger as the prime suspect in the case.
A cell phone owned by Kohberger was near the victims’ home ten times prior to the murders.
A white sedan reportedly matching Kohberger’s was caught on surveillance footage repeatedly driving past the rental home around the time of the murders.
Ka-Bar, the company that made the knife used in the murders, has denied that anyone named Kohberger purchased a knife from them. They sell to both retailers and direct to consumers, with a “fixed handle knife” for about $139.
This has been confirmed by a spokesperson for the company TMZ Moscow police and other agencies contacted the company asking about KA-BAR knives and sheaths.
Law enforcement officials asked the company on Nov. 13 to identify that the scabbard belonged to them, which they confirmed.
But they have no record of anyone by the name of Kohberger purchasing a knife case or other products directly from them.
Sources say the scabbard found at the scene belonged to a seven-inch knife, traditionally used as a hunting tool.
Ka-Bar says it has been made since World War II and can be used for chopping firewood or cutting wire and rope.
Kohberger is being held in the Latah County Jail in Moscow, Idaho, on charges of first degree murder and burglary. His trial begins on October 2. In May, the suspect offered to ‘keep silent’ in the case.
It is unusual, but not unheard of, for defendants to remain ‘silent’ in criminal cases. Sometimes this is done because defendants and their attorneys feel they need more time to weigh the consequences of entering a plea of guilty or not guilty; other times it may be part of a broader legal strategy or simply a defendant’s personal choice.
Kohberger refused to waive his right to a speedy trial. It is still possible that the trial, which is expected to take six weeks, will be postponed or moved to another location.
Prosecutor Bill Thompson has until the end of July to determine whether his office will seek the death penalty in the case. Several of the victims’ families have expressed their wish that Kohberger receive the death penalty in the case.
Shanon Gray, the Goncalves family’s attorney, told me NewsNation in May: “We have spoken to the District Attorney about the case, Mr. Thompson. He is going to meet all the families individually and make a decision based on that.