Lawyers for accused Idaho killer Bryan Kohberger want their own DNA expert to examine the prosecution’s use of forensic genetic genealogy to identify their client as the killer of four University of Idaho students last November.
In an affidavit filed in support of the defense motion for detailed access on the prosecution’s use of DNA evidence, Dr. Leah Larkin highlights the differences between DNA profiles from consumer tests like 23andMe and specialized labs, KHQ reports.
Using a DNA sample found on the snap of a knife sheath left at the scene of the crime, prosecutors have said that they obtained a link to Kohberger’s DNA through his father’s DNA profile, but his defense questions the method’s validity and constitutionality.
Larkin said that the consumer sites could bring about “phantom matches” results and that the science behind the results aren’t always accurate.
“A poor quality kit might have too few matches or it just might have phantom matches that are not real measures of relationship,’ court document read. “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.”
“Any given centimorgan amount can represent more than one possible relationship.”
After narrowing down the suspect list with genealogical DNA, prosecutors say a DNA sample from Kohberger himself, taken after his arrest, matched the knife sheath sample directly. If the defense can invalidate the forensic genealogy work, however, they would have grounds to ask the judge to disallow the direct match.
The prosecution has opposed giving the defense complete access to the genealogical data, citing privacy concerns for the people identified in it who were not considered suspects.
As CrimeOnline previously reported, Kohberger is facing charges for the murders of Madison Mogen, Kaylee Goncalves, Xana Kernodle, and Ethan Chapin. All four students were found stabbed dead in their off-campus rental near the school in November 2022.
Police arrested Kohberger in December 2022 at his family’s home in Pennsylvania. He was extradited back to Idaho to face charges.
Kohberger remains behind bars without bail. Check back for updates.
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[Feature Photo: Bryan Kohberger, who is accused of killing four University of Idaho students, is escorted to an extradition hearing at the Monroe County Courthouse in Stroudsburg, Pa., Tuesday, Jan. 3, 2023. (AP Photo/Matt Rourke, Pool)]
