Idaho College Murders: Bryan Kohberger's Defense Team Claims DNA 'Phantom Matches' May Throw Case Into Doubt

The defense team for Bryan Kohberger, the suspect accused of stabbing four college students to death in Idaho last fall, is currently challenging the evidence used by investigators, stating there are potential weaknesses in the credibility of the genetic genealogy method that was used to arrest him, according to authorities.

As Front Page Detectives previously reported, the defense filed a motion for detailed access on the prosecution’s use of DNA.

In an affidavit filed in support of that motion, Dr. Leah Larkin highlights the differences between DNA profiles from consumer tests like 23andMe and specialized labs, NewsNation reported.

Prosecutors used a DNA sample found on the snap of a knife sheath left at the scene to link to Kohberger’s DNA through his father’s DNA profile, but now the defense is questioning the method’s validity and constitutionality.

In the affidavit, Larkin states the consumer sites could bring about “phantom matches” results and the science behind those results are not always accurate.

In the court document, Larkin said, “A poor quality kit might have too few matches or it just might have phantom matches that are not real measures of relationship. In the absence of effective oversight, forensic genetic genealogists are on an ‘honor system’ to obey the Terms of Services and the Department of Justice Interim Policy on forensic genetic genealogy.”

Larkin added, “Any given centimorgan amount can represent more than one possible relationship.”

Prosecutors narrowed down the suspect list with genealogical DNA. After Kohberger was arrested, they took a DNA sample from Kohberger himself, which matched the knife sheath sample directly.

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The defense is now trying to invalidate the forensic genealogy work, which would give them grounds to ask the judge to disallow the direct match, NewsNation reported.

Prosecutors have opposed giving the defense complete access to the genealogical data, citing privacy concerns for the people identified in it who were not considered suspects.

Kohberger, 28, was studying for a Ph.D. in criminology at Washington State University when police believe he broke into a home in Moscow, Idaho, and fatally stabbed four students — Kaylee Goncalves, 21; Madison Mogen, 21; Xana Kernodle, 20; and Kernodle's boyfriend, Ethan Chapin, 20 — in November 2022.

Two roommates who were home at the time were not harmed during the deadly attack.

Kohberger is currently behind bars without bail, and if found guilty, could potentially be sentenced to death.