Signal Tracker Helps Search for Missing 84‑Year‑Old

Investigators are using a new tool that can find the tiny radio waves from devices like pacemakers. The device, called a “signal sniffer, ” was made by former NSA hacker David Kennedy. He says the pacemaker Nancy Guthrie wears sends a Bluetooth signal every few minutes. Nancy, 84, vanished from her home in Tucson on February 1 after missing church. Her pacemaker stopped connecting to the app on her phone at 2:28 a. m. That break in connection shows the pacemaker uses Bluetooth Low Energy, a low‑power mode that keeps devices running for years. Kennedy tested the sniffer at home with a simple drone and cheap parts. He could extend its reach to about 800 feet, far beyond the usual 10‑15‑foot range.With stronger antennas or drones that fly higher, the signal could be picked up from many hundreds of feet away. A helicopter carried the sniffer over the search area on Monday. The low‑altitude flight helped give a broad picture of where signals were coming from. Kennedy thinks drones would be better because they move faster and avoid interference from metal or concrete structures. This technology is new for police work, so they don’t yet have many drones ready to use. If 50 or more drones could patrol a large area, the search time might shrink from weeks to just days. The main limits are how many drones can fly and who can control them.