In a gripping high-tech twist that’s captured the nation’s attention, a battle-hardened former Marine and elite ethical hacker has revealed he built a powerful Bluetooth “signal sniffer” specifically to track down the missing pacemaker of 84-year-old Nancy Guthrie — the beloved mother of Today show co-host Savannah Guthrie — and he’s now turning the innovation into a revolutionary app that could turn every smartphone in Tucson into a desperate search tool.

Nancy Guthrie, the warm, vibrant grandmother who vanished in the dead of night from her Catalina Foothills home near Tucson, Arizona, on February 1, remains the centre of one of America’s most baffling abduction mysteries. Chilling doorbell camera footage shows a shadowy figure tampering with her security system around 1:47 a.m., just minutes before her pacemaker app disconnected from her phone at 2:28 a.m. — a chilling “unbiased witness” timestamp suggesting she was forcibly taken from her bed.

With no ransom demands confirmed, family members cleared as suspects, and over 40,000-50,000 tips flooding in, investigators from the Pima County Sheriff’s Department and the FBI have turned to cutting-edge tech in their third-week push for answers.

Enter David Kennedy, CEO of cybersecurity firm TrustedSec, a former Marine who once conducted cyber missions for the National Security Agency. Kennedy exclusively told outlets he sprang into action the moment details emerged about Nancy’s Bluetooth-enabled pacemaker.

“When this whole Nancy Guthrie case broke, law enforcement revealed her pacemaker had disconnected from her phone — a clear sign it’s one of the newer models with Bluetooth Low Energy connectivity,” Kennedy explained. Having previously tested pacemaker security for major manufacturers to prevent life-threatening hacks like battery drainage or short-circuiting, he knew exactly what to do.

“I wrote a software tool that specifically hunts for Bluetooth low-energy devices,” he said. “Bluetooth transmits at very low power, but with signal amplifiers, high-gain antennas, and software-defined radios, we can massively extend the detection range.”

Kennedy’s custom sniffer, now mounted on a low-flying Pima County Sheriff’s helicopter, boasts a proven range of up to 800 feet — and in ideal conditions with clear line-of-sight, potentially 5,000 feet. It’s not two-way communication; instead, it creates a “massive bubble” of detection energy to ping the tiny 10-milliwatt signal from Nancy’s implanted device.

To prove it works even in tough spots, Kennedy tested by hiding a Bluetooth device in his armpit — mimicking the pacemaker buried inside a person’s body. “It filters out the millions of other Bluetooth signals out there,” he stressed. “We’re homing in only on Nancy’s specific physical address.”

Even MAC address randomization — a privacy feature that hides device identities — can’t fool it. Using an identity-resolving key from the original phone pairing, the sniffer can unmask and lock onto her exact pacemaker.

But challenges remain: The device’s weak signal pings every few minutes, requiring precise timing and triangulation. Walls, terrain, or — terrifyingly — deliberate tampering by captors could kill the signal entirely. “It’ll take luck,” Kennedy admitted. “You have to be right over the spot when it transmits.”

That’s why he’s pushing his boldest idea yet: a public app for iPhone and Android. “I’ve already built prototypes with a colleague,” he revealed. “If we get her device’s physical address, anyone can download it, hit ‘Find Nancy,’ and their phone scans passively in the background. Any hit pings law enforcement with GPS coordinates for immediate triangulation.”

Imagine thousands of Good Samaritans in Tucson and beyond turning their phones into a city-wide detection network — crowdsourcing the search in real time. “I could publish it tomorrow,” Kennedy said. “Every download becomes another scanner telling the FBI: ‘There’s a hit here — go now.'”

The Pima County Sheriff’s Department has deployed the sniffer-equipped chopper in grid searches, with authorities calling it one of their “best hopes” amid DNA analysis on gloves found near the home, genetic genealogy efforts, and scrutiny of doorbell video showing a suspect’s backpack, gun holster, and ring.

Savannah Guthrie has made emotional pleas on air, sharing family photos and urging the public: “It’s never too late.” The nation watches, hearts heavy, as vigils continue and the reward swells past $200,000 from anonymous donors.

Kennedy, the ex-Marine turned white-hat hacker, insists this isn’t about fame — it’s personal. “Nancy deserves to come home,” he said. “If this tech can help bring her back to her daughter, her grandkids, her life — we’re going all in.”

As helicopters buzz over the desert and app development races forward, one question haunts every update: Will the faint Bluetooth ping from a tiny heart device lead rescuers to Nancy Guthrie before time runs out?

Anyone with information is urged to contact the Pima County Sheriff’s Department at 520-351-4900 or the FBI tip line. The search continues — and now, technology is fighting back.