Nancy Guthrie Update: Expert Reveals The One Thing That Might Still Move Case Forward

It's been 25 days since Nancy Guthrie disappeared from her Tucson home in the middle of the night. The FBI is involved. A $1 million reward is on the table. And so far, the suspect has left investigators remarkably little to work with — no usable DNA, no confirmed fingerprints, and door camera footage without timestamps. But according to the forensics expert who helped put Bryan Kohberger (the man convicted of murdering four University of Idaho students in 2022) behind bars for life, the case may not be as cold as it looks.

"The loudest evidence can be the lack of evidence," Heather Barnhart, a digital forensics expert with Cellebrite and the SANS Institute, told Fox News Digital.

The Kohberger Playbook

Barnhart analyzed the phone and computer data of Bryan Kohberger. His phone records became one of the most critical pieces of evidence in the case — not because of what they showed, but because of what they didn't.

"Kohberger literally created bookends around the crime by turning off his device," Barnhart explained. "So in addition to all the clearing and other things that he prepped for to erase his digital footprint, the fact that right before the murder, his phone was turned off, and then within like 40 minutes or so after it was turned back on, kind of gave us that tunnel to look down here."

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That deliberate blackout — a user-initiated shutdown on a fully charged phone in the middle of the night — stood out precisely because it was so unusual. And Barnhart believes whoever abducted Nancy Guthrie may have made the same mistake.

What Investigators are Looking for

The suspect who entered Nancy Guthrie's home in the early hours of February 1 was clearly prepared. He wore a ski mask, gloves, and long-sleeved clothing. He tampered with her doorbell camera. He appears to have left no traceable DNA inside the home. By physical evidence standards, he covered his tracks.

But covering your physical tracks and covering your digital tracks are two very different things — and Barnhart says the latter is far harder than most people realize.

"If the person prepped, they wouldn't ping that tower, but if they went ahead of time and scoped it out or planned, they would have," she said. "And then you can also look for entry and exit. And then proximity pings, because eventually you're going to turn your phone back on."

Even a phone on airplane mode isn't necessarily invisible, Barnhart noted. While working the Kohberger case, she discovered that her own device — on airplane mode the entire time — registered a location ping when she crossed time zones. A phone that "touches" a home's Wi-Fi network without connecting to it can still place a device at a scene. Traffic cameras throughout Pima County may have captured a vehicle or a face. And cell tower data can map a pattern of movements that reveals, over time, exactly where someone was — and when.

The Pieces Coming Together

Meanwhile, other details in the case are slowly surfacing. Neighbors have told investigators about a suspicious man seen in the Catalina Foothills neighborhood around January 11 — three weeks before Guthrie disappeared. The FBI recovered door camera images they believe may show the suspect visiting the home on an earlier date, though without timestamps — because Guthrie didn't have a Nest subscription — they can't yet confirm when the images were taken. More than 750 tips have poured in since Savannah Guthrie announced the $1 million family reward on Tuesday.

"Someone knows how to find our mom and bring her home," Savannah said in the video. "We still believe. We still believe in a miracle."

The investigation is at a critical juncture. DNA leads have stalled. The timestamp problem has complicated the camera footage. A Mexican volunteer search group, Madres Buscadoras de Sonora — which has a documented history of finding remains that others miss — traveled to Arizona to help but was denied access to key search sites by the Pima County Sheriff's Department, who stated the work should be "left to professionals."

But if Barnhart is right, the professionals may already have what they need — they just haven't found it yet.

"We hope in Nancy Guthrie, that whoever has her made a mistake," she said, "and that we can uncover that footprint."

Anyone with information is urged to contact the FBI at 1-800-CALL-FBI.