A mixture of DNA from three unidentified individuals was discovered under the fingernails of a 21-year-old University of Idaho student who was murdered along with three others in an off-campus residence in November 2022, according to a newly filed court document.

The DNA evidence was recovered from victim Madison Mogen more than two years after she and fellow students Kaylee Goncalves, 21, Xana Kernodle, 20, and Ethan Chapin, 20, were fatally stabbed in Moscow, Idaho. Bryan Kohberger, a criminology graduate student at Washington State University, has been charged with four counts of first-degree murder.

In a motion filed last Monday, Kohberger’s defense team requested that the DNA evidence be excluded from the jury’s consideration in his upcoming death penalty trial, arguing that jurors might mistakenly associate the DNA with Kohberger, despite their claim that it does not belong to him.

Attorney Bicka Barlow, a forensic DNA specialist recently added to Kohberger’s legal team, contended that introducing such testimony would violate his constitutional rights to due process, a fair trial, and the ability to confront witnesses.

Kohberger has pleaded not guilty, and his trial is scheduled to begin in August. If convicted, he faces the death penalty.

Forensic scientist Jade Miller testified before a grand jury regarding DNA test results from a swab of fingernail clippings taken from Mogen’s left hand, the motion states. The defense argued that presenting this evidence could mislead and confuse the jury, asserting that it is overly prejudicial.

The document also reveals that preliminary testing was conducted on the fingernail clippings, and a “likelihood ratio” was calculated. The defense maintains that the results were inconclusive. While the motion acknowledges that testing provided a “likelihood ratio for Mr. Kohberger,” the conclusions drawn from it have been redacted.

The defense contends that the jury could wrongly infer that the inconclusive results suggest Kohberger’s DNA was present, creating unfair prejudice against him. The motion clarifies that the DNA analysis compared two hypotheses: one suggesting the DNA came from Mogen, Goncalves, and an unknown individual, while the other proposed it belonged to Mogen and two unrelated individuals.

Mogen, a senior marketing student from Coeur d’Alene, and Goncalves were found dead in the same bed inside their King Road residence on November 13, 2022.

Attorney Misty Marris, who has closely followed the case, suggested that this new DNA finding could strengthen the defense’s strategy. She noted that DNA found under a victim’s fingernails is often associated with defensive wounds, but prosecutors might argue that such evidence can be transferred in various ways.

Defense Claims Kohberger Excluded from DNA Mixture

The defense asserts that independent laboratory testing has excluded Kohberger from the DNA mixture found under Mogen’s fingernails. However, they acknowledge that prosecutors presented this evidence to a grand jury in early 2023 while seeking an indictment against him. The state has argued that the DNA evidence was included in the grand jury proceedings as exculpatory material.

As of now, the court has not published a response from the prosecution regarding the defense’s motion.

Marris emphasized that prosecutors have an ethical duty to disclose any exculpatory evidence and suggested that the defense will likely argue that the investigation failed to explore alternative suspects.

“Their argument will be that after investigators identified Kohberger through investigative genetic genealogy, they focused solely on him and disregarded other potential leads—including this newly discovered DNA evidence,” Marris said.

The revelation adds to a growing dispute over DNA evidence in the case. The prosecution’s primary forensic evidence is a DNA sample found on a knife sheath recovered at the crime scene. Investigators used investigative genetic genealogy—combining DNA analysis with genealogical research—to trace the DNA to Kohberger’s family, leading to his arrest.

In response, the defense has repeatedly challenged the reliability, legality, and methodology of the DNA testing process. During a closed hearing last month, multiple witnesses testified about the investigative procedures used to identify Kohberger. Additionally, the defense’s recent addition of Barlow, an expert in forensic DNA analysis, suggests an effort to strengthen their challenge to the prosecution’s claims.