(NewsNation) — The lawyers representing Idaho murder suspect Bryan Kohberger are now challenging the evidence investigators used, suggesting flaws in the reliability of the genetic genealogy which investigators used to arrest him.
Investigators used genetic genealogy to link Kohberger to the crime by creating a DNA profile from a knife sheath found at the scene, which matched the profile of Kohberger’s dad, eventually leading to his arrest.
Recent court documents by Kohberger’s defense, however, dispute the imperfect nature of the science used to identify him, now scrutinizing a pivotal piece of evidence that connects him to the quadruple homicide, suggesting the DNA link may not be trustworthy.
“This is a more aggressive challenge where they’re saying wait a minute, is this fruit of a poisoned apple or something and how did you get this genealogical match? Do we know it’s a good match?,” said Dr. Greg Hamikian, a forensic biologist at Boise State University. “Maybe you got tunnel vision early on in the case through bad genealogy.”
Defense attorneys submitted an affidavit on Wednesday from Dr. Leah Larkin, a DNA expert based in California, echoing concerns that the science behind genetic genealogy is not flawless.
Larkin argues DNA profiles built by at-home test companies such as AncestryDNA or 23andMe aren’t constructed the same way as those by specialized laboratories and are not as reliable, according to her affidavit, seen by DailyMail.com.
‘A poor-quality kit might have too few matches or it just might have phantom matches that are not real measures of relationship,’ the document states.
Law enforcement is increasingly utilizing this technique to track suspects’ relatives on ancestry websites.
Unline police databases, these websites offer a broader array of relatives for investigation.
Larkin noted an example where nearly 20 possible relationship lines were listed for a match and said that’s considered a close match.
She also noted cases that she’s aware of where genetic genealogy has been wrong and cases where databases were used improperly by authorities.
Hamikian, who spearheaded the Idaho Innocence Project, emphasizes that DNA can unveil a lot, but not always the entire narrative.
“Our experience, when we worked with the police, the first hit they got through genealogy. The guy they thought was a good suspect, he’d been in the area, he sounded like a good match — they went to test him because his father had it was a close match, and it turned out the suspect was wrong,” Hamikian explained.
The crucial question remains: Will the defense’s claim impact Kohberger’s plea of not guilty in the deaths of Ethan Chapin, Madison Mogen, Xana Kernodle and Kaylee Goncalves?
Kohberger is currently incarcerated, and if found guilty, could potentially be sentenced to death.