On a chilly Thanksgiving in 2022, while most families gathered around tables for turkey and pie, a very different mission was unfolding.
Thousands of miles apart, grief-stricken parents in Washington were mourning their son, while a team of scientists in Texas gave up their own holiday to chase down the identity of a killer.
What they uncovered that weekend would not only bring answers but also change the course of one of the most haunting murder cases in recent American history.
The Knife Sheath That Held a Secret
Investigators in Moscow, Idaho, had stumbled upon a critical clue: a leather knife sheath left at the scene of a brutal quadruple homicide that shocked the nation.
Four University of Idaho students — Ethan Chapin, Xana Kernodle, Madison Mogen, and Kaylee Goncalves — had been savagely stabbed inside their off-campus home.
The sheath contained a single male DNA sample, but when run through CODIS, the national criminal DNA database, it yielded no match.
With the killer still at large and panic setting in, law enforcement decided to try something new — they sent the sample to Othram, a cutting-edge forensic genealogy lab in Texas.
Building a Family Tree from One DNA Strand
Othram’s team used advanced genome sequencing to create a detailed DNA profile.
Instead of looking for exact matches, this technology could trace far-flung relatives and build family trees.
Within 48 hours, the scientists had narrowed the DNA to just two families in the U.S., both from Pennsylvania, both with a distinct Italian heritage.
From there, other pieces of the puzzle clicked: a white Hyundai Elantra spotted near the crime scene, license plates suspiciously changed after the murders, and a man with bushy eyebrows who happened to be a criminology PhD student at Washington State University.
His name was Bryan Kohberger.
Closing in on the Suspect
With a likely suspect in view, investigators tracked Kohberger back to his parents’ home in Pennsylvania.
Pretending to be trash collectors, officers recovered garbage containing his father’s DNA — a near-perfect match to the DNA from the knife sheath.
On December 29, 2022, just six weeks after the murders, Kohberger was arrested.
For Ethan Chapin’s mother, Stacy, the call from police confirming the arrest brought a moment of relief in the middle of unimaginable pain.
“It closed a chapter,” she said. “We didn’t have an unknown anymore.”
Thanksgiving Without Ethan
That first Thanksgiving after the murders had been unbearable for the Chapin family.
Instead of a holiday meal, they stayed home and ate tacos, trying to fill the silence left by Ethan’s absence.
Only later did Stacy learn that, while her family grieved, the Othram team was giving up their own Thanksgiving to identify her son’s killer.
“It was a moment where our paths crossed,” Stacy recalled.
“They were doing everything they could to help us, and we didn’t even know it.”
The DNA Fight in Court
Kohberger’s defense team fought hard to suppress the genetic genealogy evidence, arguing it was unconstitutional and trying to discredit Othram’s experts. But the judge dismissed those motions.
With DNA from the murder weapon standing as the strongest piece of evidence, Kohberger eventually pleaded guilty in July 2025 and was sentenced to life without parole.
A Tool That Could Save More Lives
Experts like Kristen Mittelman of Othram believe this case shows why genetic genealogy must become a standard tool for law enforcement.
Unlike CODIS, which only matches close relatives, genealogy technology can identify distant family connections that help pinpoint suspects.
But without federal funding, many police departments can’t afford it.
“In many cases, offenders are serial,” Mittelman explained. “We need to catch people the first time, not the fiftieth.”
Turning Grief Into Advocacy
Today, the Chapin family is working alongside Othram to advocate for wider access to genetic genealogy, hoping other families won’t have to endure the same agonizing wait for answers.
Stacy and her daughter Maizie have even visited the lab in Texas, seeing firsthand where scientists had worked through their holiday to bring justice for Ethan.
“Life brought us together in circumstances that are not ideal,” Mittelman said.
“But Stacy has given this technology the voice and face it needs.”
A Different Kind of Thanksgiving
Now, with Kohberger behind bars, the Chapin family feels ready to celebrate Thanksgiving again.
“It’s always going to be different,” Stacy admitted, “but it’s okay. We have to celebrate what we still have.
And I wouldn’t change one thing about those 20 years with Ethan. He was amazing.”