FBI Tracks Pacemaker Signal — Nancy Guthrie Located

TUCSON, Ariz. (KOLD/Gray News) – As the search for 84-year-old Nancy Guthrie enters its third week, the FBI is employing new technology that could help locate her using signals from her pacemaker.

Law enforcement is working with a device known as a “signal sniffer” that uses an amplifier to find Bluetooth signals and identify the unique MAC [Media Access Control] address of Guthrie’s pacemaker using a directional antenna.

“It’s got software running in it, continuously scans, and if it doesn’t recognize (hers), it just eliminates it until it locks onto the right one,” said Morgan Wright, CEO and founder of the National Center for Open and Unsolved Cases.

Wright, who also analyzes true crime cases on Substack, said the process is similar to walking around with Guthrie’s cellphone and waiting for a Bluetooth connection request but on a much larger scale.

The FBI has been attaching the device to low-flying helicopters, according to Wright, as they continue to search for Guthrie, who was last seen Jan. 31.

The FBI says new images show an armed individual appearing to have tampered with the camera at Nancy Guthrie’s front door the morning of her disappearance.(FBI Most Wanted)

However, Wright believes the helicopters could interfere with the signal’s reception and not get low enough to connect. That’s why he and cybersecurity expert Dave Kennedy developed the device for a drone instead.

“We could fly a whole fleet of drones because you can program them to do a search grid, use AI [artificial intelligence] to program them to do a search grid, and cover a huge area with three or four drones,” Wright said.

The new device also has a much higher level of detecting a signal, with a range of about 1,000 feet.

“Instead of trying to make the haystack smaller, it’s using a bigger magnet to pull that needle out,” Wright said.

Wright said the FBI is now working to get the technology in the air and believes it could be a turning point in narrowing down the timeline of Guthrie’s disappearance and where she might be now.

“The pacemaker, it’s not the only piece that will do it, but it’s one of the most vital pieces,” Wright said. “It generates all the additional events and actions, comes from the behavior of that pacemaker.”

Wright said pacemaker telemetry data could serve as an unbiased witness in the case.

“The pacemaker is the most unbiased witness we have – why? Because it’s sending telemetry data,” Wright said.

The FBI has the prototype of the new device and could start using the drones within the next few days, according to Wright.

The FBI increased its reward up to $100,000 for information leading to the location of Nancy Guthrie.(FBI Phoenix)

Investigators are also working with Walmart management to develop leads because a backpack the suspect was seen wearing is sold exclusively at their stores, The Associated Press reports.

The backpack, a 25-liter “Ozark Trail Hiker Pack,” can be seen in surveillance videos released of a masked person outside Guthrie’s front door the night she vanished. In addition to the backpack, the person was wearing a ski mask, long pants, a jacket and gloves.

Authorities say it’s also possible that the suspect’s clothing was bought at Walmart, but none of those items are exclusive to the retailer.

The FBI said the suspect in the surveillance footage is a man who is about 5 feet, 9 inches, tall with a medium build.