How 'signal sniffers' and a pacemaker are being used to find Nancy Guthrie

'Signal sniffers' used to detect missing person Nancy Guthrie's pacemaker ABy Annika BurgessTopic:Missing Person5m ago5 minutes agoMon 16 Feb 2026 at 4:27amSavannah Guthrie (left) has not been on the Today show since the disappearance of her mother, Nancy. (Supplied: Instagram)In short:The FBI is using advanced bluetooth technology to try to find Nancy Guthrie's pacemaker.Pacemakers emit signals that could provide clues to the whereabouts of the missing 84-year-old.What's next?A digital forensic expert says it is possible to locate a person through pacemaker signals, but there are limitations. abc.net.au/news/nancy-guthrie-pacemaker-signal-sniffer-suspected-kidnapping-fbi/106348848Link copiedShareShare articleFlying helicopters low and slow over the Tucson desert in Arizona, the FBI has been using "signal sniffers" to try to locate Nancy Guthrie's pacemaker. As the search for the 84-year-old mother of US Today show anchor Savannah Guthrie entered its third week, investigators took to the sky with advanced bluetooth technology.They were hoping to pick up on signals emitted from the device implanted in Ms Guthrie's chest to help trace her whereabouts, US media outlets NewsNation and Fox News reported.A digital forensic expert says pacemakers can provide clues to a missing person's whereabouts, but there are limitations. Pacemakers a 'sensor' on the bodyPacemakers are small, battery-powered devices inserted in the chest, sending continual electrical signals to the heart to keep it in a regular rhythm.DNA recovered from glove found near Guthrie homeThe FBI says a glove containing DNA was found near the home of US TV show host Savannah Guthrie's mother and appears to match those worn by a masked person outside her front door the night she vanished.These days, many pacemakers connect via bluetooth to a person's mobile phone to transmit data about the heart's performance.Pacemakers do not have any kind of built-in GPS, but use Bluetooth Low Energy (BLE), which emits electromagnetic signals that could be detected. Matthew Sorell, a digital forensic expert from Adelaide University, said it had become common practice to attempt to track victims or missing persons through their devices."Whether it's a mobile phone or a smart watch or a plugable device," Dr Sorell said."There's now a range of health technologies, including pacemakers, glucose monitors, heart rate and blood pressure monitors, where effectively you're able to put a sensor on the body and it connects to your phone."Savannah Guthrie alongside her mother while hosting NBC's Today Show live from Australia. (Getty Images: Don Arnold/WireImage)Slow, low, sweep of the areaNancy Guthrie was last seen at her Tucson home on January 31 and was reported missing the following day. Authorities say her blood was found on the front porch. New images, FBI raises reward in search for Nancy GuthrieThe FBI increases its reward and releases new images as part of its investigation into the suspected abduction.Purported ransom notes were sent to news outlets, but two deadlines for paying have passed.Over the weekend, local media reported a Pima County Sheriff's Department helicopter flying low, in a grid around the area of Nancy Guthrie's home.The helicopter had reportedly been fitted with a small device known as a "signal sniffer", described as "sophisticated FBI technology" to help pick up her pacemaker's signal.Maureen O'Connell, a former FBI special agent, said the agency was likely employing a variety of technologies to find Ms Guthrie."With regards to this particular tool … I do know that the pacemaker sends off a very short-distance alert … so they're going to have to get really close," Ms O'Connell told NewsNation.A Pima County Sheriff's Department deputy patrols at the home of Nancy Guthrie. (Reuters: Rebecca Noble)Dr Sorell said the range of a pacemaker signal was generally about 10 to 30 metres, so investigators would need to use a high-gain antenna tracking backwards and forwards slowly from the air.High-gain antennas increase signal strength by focusing radio energy into a narrow beam."You basically need to sweep slowly. If the device can see that radio signal, you need to give it about 10 to 15 seconds to respond," Dr Sorell told the ABC."So they're essentially sending out a paging signal looking for that device. If it's in range, then it will hopefully respond in time."Any data transmitted from the pacemaker would only provide insights into Ms Guthrie's location, not the state of her health, Dr Sorell said. Neighbours of Nancy Guthrie show support for the family in Tucson, Arizona. (AP: Sejal Govindarao)Pacemaker disconnected from phone Authorities believe Nancy Guthrie went missing during a 41-minute window in the early morning of February 1.It was about 1:47am when her doorbell camera was disabled.Last week, the FBI released su