How a family tree and DNA identified Idaho murder suspect Bryan Kohberger
Detectives sent DNA to a private lab in one of the first cases of using genealogy to solve a hot case
Detectives sent DNA to a private lab in one of the first cases of using genealogy to solve a hot case
Detectives sent DNA to a private lab in one of the first cases of using genealogy to solve a hot case
When Moscow, Idaho, detectives entered the horrifying crime scene where four university students were found mysteriously stabbed to death on Nov. 13 – they discovered a major clue – a Ka-Bar knife sheath — lying on the bed next to one of the bodies.
But the DNA they found on that sheath led them nowhere – at first.
Because not a single match came up on the national criminal DNA database.
So whose DNA was it?
That's when investigators came up with a novel idea that up until now was typically used only in cold cases – they sent the DNA to a private lab to see if they could find a match on a public ancestry database.
And it worked.
"Genetic genealogy was crucial in identifying the defendant in the Idaho murder case," said Palm Beach County State Attorney Dave Aronberg.
According to a source close to the investigation, the private lab entered the DNA into a public ancestry database, and within days, cousin matches were showing up.
Genealogists then start the tree with the closest cousin they can.
"We use tools such as Ancestry.com to help build those trees. So once you get this individual's name, you can start building their family tree. And there's a lot of public records," said forensic scientist Julie Sikorsky of the Palm Beach County Sheriff's Office.
Meantime, detectives were still looking for other clues.
And they got a big one.
Surveillance cameras caught a white Hyundai Elantra driving around the crime scene at the time of the murders
On Nov. 25, police asked other law enforcement to be on the lookout for white Elantras.
And four days later, Washington State University police say they found at least one — registered to Bryan Kohberger.
But did that name mean anything to the police at the time?
Apparently not, because police made a public plea for information about white Elantras on Dec. 7.
They began sorting through over 22,000 registered Elantras. It was the proverbial needle in a haystack.
And that's where genetic genealogy became so crucial.
A source says within days, the lab handed over the tree leading to the Kohberger family and their only son Bryan, who drives a white Elantra.
"And now you find out that he's living less than ten miles away. You've got a prime suspect," said retired FBI Special Agent John MacVeigh.
Detectives got search warrants for Kohberger's phone and started tracking him.
He drove home to Pennsylvania with his father for Christmas, and agents retrieved some of the family’s trash.
They ran DNA on it and find Kohberger’s father, Michael, is likely to be the father of whoever left the DNA on the knife sheath.
They arrest Bryan Kohberger the next day.
"Now, with such a high profile case, I think that police departments all across the country are going to want to try to follow the lead in Idaho because it's incredibly powerful," said Aronberg.
Rapid results in a baffling case that could have taken months to solve or even gone cold.
MacVeigh says this tool could change crime solving forever — and should have a chilling effect on criminals.
"Because you never know when they're going to knock on your door and say, 'Hey, we got a match,'" said MacVeigh.
You might wonder why there is no mention of genetic genealogy in the probable cause arrest affidavit.
That’s for two reasons:
- Police don’t need to include every lead they get that brings them to their suspect – just enough to convince a judge to sign the arrest warrant.
- Law enforcement has been divided on whether revealing this information might lead to people being reluctant to sign up for ancestry databases if they think it might be used to solve criminal cases.
Right now, only two public genealogy databases allow law enforcement to use their data, and in one of them, you have to consent to your DNA being used by police.
But some experts say people already have so much personal information online, and so many have used ancestry kits, that it is becoming a lesser concern.
Aronberg agrees: many people don’t care if their DNA eventually helps find and convict a distantly related killer.