The Golden State Killer terrorized California for a decade – 13 murders, more than 50 rapes – and walked free for 40 years because investigators couldn't keep their own tactics straight.
Now Nancy Guthrie's kidnapper is sitting on a ticking clock, and the most powerful forensic weapon in American law enforcement history is pointed directly at him.
But the man running this investigation may have already handed the suspect a head start.
Nancy Guthrie DNA Evidence – Why Genetic Genealogy Will Identify the Suspect
The FBI confirmed this week that investigators are deploying investigative genetic genealogy – the same science that unmasked the Golden State Killer in 2018 and brought Bryan Kohberger to justice for the Idaho murders – on DNA recovered inside Nancy Guthrie's Tucson home and on a glove found two miles from the property.
This isn't a hail mary.
DNA expert CeCe Moore, chief genetic genealogist at Parabon, told NBC's Today show that the kidnapper "will be identified" through this technique.
"If I was the kidnapper, I would be extremely concerned right now," Moore said.
The science works even when the suspect has no prior criminal record and no entry in the FBI's CODIS database – which is exactly the situation investigators face here, since neither the DNA found inside Guthrie's home nor the glove sample matched anything in standard law enforcement databases.
Forensic genealogy casts a wider net, comparing hundreds of thousands of genetic markers against public ancestry databases to surface distant relatives – third cousins, fourth cousins – and then building family trees backward to the suspect.
It identified Joseph DeAngelo from relatives who didn't even know they had a killer in the family.
The reward for information has now hit $200,000 following an anonymous $100,000 donation to the 88-CRIME tip line, on top of the FBI's existing $100,000 offer – and investigators have fielded more than 19,000 tips since Guthrie vanished on February 1.
Trump Blasts Pima County Sheriff Nanos Over Pacemaker Disclosure
Here's where this gets uncomfortable for Pima County Sheriff Chris Nanos.
President Trump boarded Air Force One Thursday and said what every retired FBI agent was already thinking.
"I didn't like when they talked about going after the pacemaker before they even started going after it," Trump told reporters, referring to the public disclosure of the FBI's Bluetooth "sniffer" technology – a device used to detect signals from Guthrie's pacemaker – before the search had been fully deployed.
"If in fact they could do it that way, the person would say, 'Well, I'm not going to let that happen,'" Trump added.
Retired FBI supervisory special agent James Gagliano validated every word of it on Fox News Friday morning.
"The president's point was well taken," Gagliano said, noting that "sometimes we might give the bad guys too much information."
Gagliano went further – and this is the part Nanos should be reading carefully.
The sheriff has been conducting individual media interviews that contradict each other, walking back statements, and releasing information through "fits and starts" instead of running structured press conferences through a public affairs office.
"I don't think this is the best way to conduct the messaging in a case this large," Gagliano said.
Three weeks in. An 84-year-old woman still missing. A six-figure reward unclaimed. And the man leading this investigation has been running press availability like a solo act.
The Case That Can't Afford Any More Mistakes
Trump has already said the kidnapper should face the death penalty if Nancy Guthrie doesn't come home alive.
That outcome isn't inevitable – and that's the point.
The Golden State Killer evaded capture for 40 years not because of superior intelligence, but because investigators were working with inferior tools and fragmented information management.
The tools are no longer inferior.
Forensic genetic genealogy doesn't need the kidnapper to have a criminal record, a relative who talks, or a mistake on camera – it needs a viable DNA sample and time.
Investigators are also working with Walmart to trace sales records on the Ozark Trail backpack worn by the suspect – a detail that could generate its own lead through credit card and surveillance records.
The $200,000 reward, the 19,000-plus tips, the most powerful DNA identification system ever developed – all of it is converging on whoever is holding Nancy Guthrie right now.
Trump saw the communication breakdown and called it out publicly.
The retired FBI agents are saying the same thing in more measured language.
And the science is doing what it always does – closing the distance between a suspect and a cell.
Sources:
- Jasmine Baehr and Greg Norman-Diamond, "New DNA Strategy Could Help Identify Suspect in Nancy Guthrie Disappearance," Fox News, February 20, 2026.
- Greg Norman-Diamond and Landon Mion, "Trump Slams Investigators for Disclosing High-Tech FBI 'Sniffer' Searching for Pacemaker," Fox News, February 20, 2026.
- Greg Norman-Diamond, "Retired FBI Agent Questions Pima County Sheriff's Approach, Says Trump's Criticism Is 'Well Taken,'" Fox News, February 20, 2026.
- Stephanie Mansour and Pilar Melendez, "Arizona Authorities Turn to Genetic Genealogy in Ongoing Search for Savannah Guthrie's Mom," NBC News, February 19, 2026.
- Matt Finn, "Genetic Genealogy That Caught Notorious Killers Now Used in Nancy Guthrie Case," Fox News, February 18, 2026.