A groundbreaking technological effort is underway in the search for Nancy Guthrie, the 84-year-old mother of NBC “Today” co-anchor Savannah Guthrie, who vanished from her Tucson, Arizona home in the early hours of February 1, 2026. David Kennedy, a former U.S. Marine and founder of cybersecurity firm TrustedSec, has engineered a specialized Bluetooth Low Energy (BLE) signal sniffer designed explicitly to detect the unique signature of Guthrie’s pacemaker. Mounted on a Pima County Sheriff’s Office helicopter, the device is conducting aerial sweeps over the Catalina Foothills and surrounding desert terrain in hopes of capturing the faint transmissions from the implanted medical device.

The critical timestamp emerged from forensic analysis of Guthrie’s phone: at 2:28 a.m., the pacemaker abruptly disconnected from its companion monitoring app. This occurred shortly after the Nest doorbell camera recorded a masked figure approaching the residence at 2:12 a.m., and the camera itself went offline around 1:47 a.m. Investigators interpret the disconnection as evidence that Guthrie was rapidly moved out of Bluetooth range—typically limited to 30-50 feet—or that the device was tampered with or powered down. BLE-enabled pacemakers periodically broadcast signals to sync data like heart rate and battery status; when out of range, they increase transmission attempts, creating detectable pings.

Kennedy, who has a background in offensive security testing for medical device manufacturers, recognized the potential immediately. Pacemakers use BLE with a fixed physical MAC address for pairing, though randomization features obscure it during normal use. By extracting Guthrie’s specific MAC (potentially via identity-resolving keys from prior app data or manufacturer cooperation), Kennedy’s software filters out ambient Bluetooth noise—millions of signals in a populated area—and isolates the target. His enhancements include high-gain directional antennas, signal amplifiers, and software-defined radios that extend detection range dramatically. Tests showed reliable pickup at 800 feet, with theoretical reach up to 5,000 feet under optimal conditions like clear line-of-sight from altitude.

To simulate real-world challenges, Kennedy conducted field trials by hiding a BLE beacon under his clothing to mimic body attenuation from tissue and implantation. Results confirmed the device’s viability even with reduced signal strength. A trusted colleague assisted in transporting the prototype to Arizona, where it was integrated with the sheriff’s aviation unit for grid-pattern flights at low altitudes to maximize coverage over rugged, sparsely populated areas.

The innovation does not stop at aerial deployment. Kennedy is fast-tracking a companion mobile app for iOS and Android that would allow the public to participate in passive scanning. Users would select the “Find Nancy” function, granting the app permission to monitor nearby BLE signals in the background. If a match to Guthrie’s MAC is detected, the app would anonymously report the geolocation to law enforcement for immediate triangulation. “We could turn every smartphone in Tucson—and beyond—into a node in a massive detection network,” Kennedy stated. Development is progressing rapidly, with beta testing planned once legal and privacy approvals are secured.

The broader investigation remains exhaustive. Pima County Sheriff’s deputies, FBI agents, and over 400 personnel have processed more than 50,000 tips. A black glove recovered two miles from the home matched the suspect’s in doorbell footage, yielding unknown male DNA submitted to CODIS—no hits yet, but further genealogy analysis is underway. New trace evidence from inside the residence is being examined. Sheriff Chris Nanos reiterated that the Guthrie family—including Savannah, siblings Annie and Camron, and spouses—has been fully cleared, labeling them “victims plain and simple” and condemning cruel online speculation.

Savannah Guthrie continues her public appeals, most recently posting a solo Instagram video emphasizing hope: “It’s never too late to do the right thing. You’re not lost or alone.” Earlier ransom demands sent to media outlets expired without resolution. Authorities maintain an open posture, with no confirmation of harm to Guthrie, who requires daily medication and manages cardiac conditions via her pacemaker.

Technical hurdles remain formidable. Pacemaker signals are weak, easily attenuated by terrain, structures, or deliberate shielding. The device could have been removed, disabled, or its battery drained. Successful detection requires being within enhanced range during an active transmission window, demanding precise flight paths and timing. Weather, battery life of the sniffer equipment, and interference from urban Bluetooth clutter add complexity.

Kennedy’s work bridges ethical hacking and humanitarian search efforts. His prior research exposed pacemaker vulnerabilities—such as remote battery exhaustion or command injection—but always with manufacturer consent to improve security. This application repurposes that expertise for life-saving purposes, showcasing how cybersecurity tools can aid missing persons cases.

As the search enters its third week, the helicopter sweeps continue alongside ground teams, K-9 units, and drone operations. The potential app launch could exponentially increase detection probability if scaled nationwide. Public support remains strong, with vigils, social media campaigns, and a growing reward fund.

The nation holds its breath for any ping that could lead rescuers to Nancy Guthrie. Authorities urge anyone with information to contact the FBI at 1-800-CALL-FBI or Pima County Sheriff’s Office. In a case defined by endurance and innovation, this Bluetooth hunt represents a powerful fusion of technology and hope—one signal away from resolution.