Man accused in Idaho college student killings loses bid to toss DNA evidence
A judge has allowed key DNA evidence to be presented in the upcoming trial of Bryan Kohberger, evidence which prosecutors say links him to the fatal stabbings of four Idaho college students in November 2022.
New details from a closed-door, cameras-off proceeding last month show how Kohberger's defense team tried to exclude the evidence they said was improperly obtained. But Judge Steven Hippler ruled the DNA and records from his cell phone and online accounts, which investigators got through search warrants, could be included. A transcript of the hearing was released Friday.
Kohberger, now 30, is accused in the deaths of Madison Mogen, 21; Kaylee Goncalves, 21; Xana Kernodle, 20; and Ethan Chapin, 20. The four were found stabbed to death in their rental house close to the University of Idaho campus on Nov. 13, 2022. Kohberger was arrested in late December of that year, after the town of Moscow was put on edge over the killings and lack of a suspect for weeks.
Authorities said they linked him to the crimes using DNA that was found on a knife sheath left behind at the scene. In the unsealed transcript, investigators were questioned about how they identified Kohberger using a process called investigative genetic genealogy, a relatively new tool made possible by the rise in popularity of consumer genetic testing through companies like AncestryDNA and 23andMe.
Kohberger didn't prove he had a reasonable expectation of the privacy of his relatives' DNA after they willingly uploaded it to public databases, nor does the way authorities accessed that DNA impact his rights, the judge said.
Here's the latest on the case:
How Kohberger was named as a suspect using DNA
After the killings of the four students, investigators testified at the Jan. 23, 2025, hearing that they spent weeks trying to identify a suspect, the transcript shows. Their most promising piece of evidence was DNA obtained from the Ka-Bar knife sheath found near some of the victims' bodies.
They tried comparing the DNA to samples in the the Combined DNA Index System or CODIS, a database of DNA from people convicted of crimes, people who have been arrested, and DNA from other crime scenes. But they didn't get a hit.
Next, they used investigative genetic genealogy (IGG) to upload the profile of the DNA sample to public databases where people can upload their own DNA profiles. They built a potential family tree based on those results and using other sources of information like social media and birth and death records, officials said in previous court filings.
Moscow Police Detective Cpl. Brett Payne testified that Kohberger's name was first known to the investigative team on Dec. 19, 2022.
"That was a result of investigative genetic genealogy that was being undertaken by the FBI. We had a phone call that evening, and we were told Bryan Kohberger's name," Payne said.
Payne said the name was given to police only as a "tip" from the FBI, and that police then used other methods to investigate whether Kohberger was involved.
Investigators later obtained trash from Kohberger's parents' home in Pennsylvania and confirmed DNA found there belonged to the father of the person whose DNA was on the knife sheath. Later still, investigators took a swab from Kohberger's cheek and made a direct comparison.
Judge says evidence won't be tossed out
Kohberger's defense team argued in court that FBI agents who used the DNA databases did so in violation of the companies' terms of service and internal policies. Only two databases allow law enforcement to use their information – GEDMatch PRO and FamilyTreeDNA. They accessed GEDMatch and MyHeritage, which disallow such use, the judge acknowledged in his ruling.
The judge said in the ruling that any violation of the terms of service of the genetic databases or of internal FBI policy does not have bearing on Kohberger's constitutional rights.
"With regard to the violation of the databases' user policies, while this may give rise to a civil action between the FBI and the particular database or perhaps the individuals whose DNA profiles were used, Defendant has not explained how this implicates the Fourth Amendment," Hippler wrote.
IGG was a key component in the solving of the case of the “Golden State Killer” in California, who operated in the 70s and 80s and was arrested in 2018. After that case, several consumer DNA websites changed their terms of service to disallow law enforcement from accessing data, or to allow its users to opt out of law enforcement activity, according to genetic genealogist Leah Larkin, who testified in the hearing last month.
What happens next in the case?
Kohberger's trial is expected to begin on Aug. 11 after a few more scheduled pre-trial hearings, according to court records.
He faces one count of burglary and four counts of murder.
Prosecutors have said they will pursue the death penalty if Kohberger is convicted.