Authorities have recovered the DNA of an Idaho homicide suspect from a knife sheath found at the crime scene.
They compared it to the DNA of the Pennsylvania suspect’s father, recovered from the garbage.
Law enforcement’s use of public genealogy databases is increasingly common, but still controversial.
Idaho authorities recovered DNA from a knife sheath found at an Idaho homicide scene and used it to identify Bryan Kohberger as a suspect, matching it to his father’s DNA, which authorities recovered from the garbage outside his parents’ home in Pennsylvania, according to court documents released Thursday.
Kohberger appeared in an Idaho court on Thursday to answer first-degree murder charges for the deaths of Kaylee Goncalves, 21, Madison Mogen, 21, Xana Kernodle, 20, and Ethan Chapin, 20. The victims were stabbed to death in a rented home near the University of Idaho campus on November 13.
Law enforcement sources have told multiple media outlets that authorities used public genealogy databases to establish a link between a DNA sample recovered from a crime scene in Idaho and a suspect sitting at his parents’ home more than 2,000 miles away. This is the same technique that has solved many high-profile cases in recent years, identifying suspects like the Golden State killer in California and victims like Pennsylvania’s Boy in the Box.
Forensic genetic genealogy is a relatively new but fast-growing field, and its use is becoming increasingly common in active criminal investigations. The practice has also drawn criticism from privacy advocates, as police departments and government agencies across the country have abused genetic evidence in the past.
Claire Glynn, a forensic genealogy expert at the University of New Haven, told Insider that the technique is often used in criminal cases where a suspect’s DNA sample does not match in CODIS, the FBI’s linked DNA indexing system that collects DNA data from convicted felons and arrested across the United States.
In the Idaho murder investigation, authorities likely checked CODIS but found no results as Kohberger has no criminal record. According to Glynn, in the past, this obstacle could hold up an investigation for months or years. But in the case of Idaho, forensic genealogy offered a way forward.
“You sort of hit a brick wall. You have that person’s genetic code, but there’s nothing else you can do until new evidence comes to light or he’s convicted of another crime,” Glynn said. “Now we can go one step further.”
How authorities found DNA from a knife sheath in Kohberger’s parents’ garbage
Glynn said the first thing authorities would do after checking CODIS would be to subject a suspect’s DNA sample to a process known as SNP sequencing, which looks for different markers in DNA than those regularly screened in a forensic trial. This SNP sequencing is the same type of DNA analysis that companies like AncestryDNA or 23andMe perform to give customers insight into their ancestry, Glynn said.
From there, authorities upload the suspect’s SNP details to a database called GEDMatchPro, software reserved for law enforcement use in authorized criminal investigations. Authorities then compare the suspect’s SNP data with that of members of the public who have consented to their DNA being used in law enforcement investigations.
Glynn said about two million members of the public have voluntarily downloaded their DNA data from sites like AncestryDNA or 23andMe and uploaded it to GEDMatchPro. Of those two million people, at least one of them was somehow related to Kohberger and had helped lead the authorities to him.
It’s unclear which of Kohberger’s relatives submitted their DNA data to GEDMatchPro, but Glynn said it could have been someone as close as a first cousin or as distant as a fourth or fifth cousin. She said forensic genealogists would build a massive family tree around this relative, using public records such as birth records, death records, marriage records, immigration records, military records, and even social media posts to find the most recent common ancestor between suspect and relative DNA in the database.
“Ultimately, you travel back in time to this most recent common ancestor and then build it forward in time, leading you to a potential candidate identity for your suspect,” Glynn said.
Authorities usually confirm they’ve identified the right suspect by collecting DNA that the person left in a public place, such as a mug thrown in the trash or a cigarette thrown on the ground, Glynn said. In Kohberger’s case, court documents say authorities searched his parents’ trash and found DNA belonging to his father.
“On December 28, 2022, the Idaho State Lab reported that a garbage-derived DNA profile and a vaginal-derived DNA profile identified the man as not excluded as the biological father of the suspect’s profile,” the affidavit read. “It is expected that at least 99.9998% of the male population will be excluded from the possibility of being the biological father of the suspect.”
The use of genetic data by law enforcement remains a controversial practice
Forensic genetic genealogy has faced criticism in recent years regarding the ethics of consent and privacy and the lack of consistent laws and regulations governing the use of genetic material. The Americans turned out to be somewhat divided on this issue. A 2019 Pew Research Center survey found that 48% of Americans found it acceptable for consumer DNA testing companies to provide law enforcement access to genetic data, while 18% said the practice was “unacceptable”.
Meanwhile, the lack of regulation has led to a number of different practices in different jurisdictions. For example, in San Francisco, a rape victim who provided DNA in a sexual assault case was arrested after police used her genetic material in an unrelated investigation without her consent and linked her to a burglary. California legislators later passed a law expressly prohibiting law enforcement from using the DNA of sexual assault victims for unrelated investigations.
Although Kohberger’s unknown relative in the GEDMatchPro database would explicitly consent to their DNA being used in a criminal investigation, other members of Kohberger’s family tree whose names and associated public records were used in the investigation did not, according to Glynn, consent.
“By giving my consent to put my data in the database, yes, in a sense I am consenting on behalf of my other genetic relatives,” said Glynn.
But she said it’s no different than the thousands of people who are unknowingly dragged into criminal investigations each year – for example, bystanders whose faces are seen on crime scene surveillance footage or customers whose credit card details are reviewed by authorities after a business closes. robbed.
“My final argument is, is my desire for privacy… more important than public safety? Which is more important than the other?” Glynn said. “Public safety is the most important thing to me.”
Read the original article on Insider