Authorities Use 'Signal Sniffer' in Search for Missing Nancy Guthrie

Former FBI agent says technology could help detect Guthrie's pacemaker signal

Published on Feb. 15, 2026

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As the search continues for 84-year-old Nancy Guthrie, who went missing from her Tucson, Arizona home on January 31, authorities have deployed a 'signal sniffer' mounted on a helicopter in an attempt to detect the signal from Guthrie's pacemaker. Guthrie's pacemaker was disconnected from her phone app shortly before her disappearance, and investigators believe she may have been abducted.

Why it matters

The use of the 'signal sniffer' technology highlights the lengths authorities are going to in order to locate Guthrie, who is the mother of 'TODAY' show anchor Savannah Guthrie. The disappearance has garnered national attention, and the investigation has received thousands of tips as authorities work to determine what happened and find Guthrie.

The details

The 'signal sniffer' device was spotted on the skid of a Pima County Arizona Sheriff Department helicopter that was seen flying low over the Tucson area. Former FBI special agent Maureen O'Connell says the technology is likely being used because Guthrie's pacemaker sends out a short-range alert signal that authorities would need to get close to in order to detect. Guthrie's Nest Cam was also disconnected shortly before her pacemaker was disconnected the night she went missing.

  • Nancy Guthrie was last seen at her home on January 31, 2026 in Pima County, Arizona.
  • Guthrie's pacemaker was disconnected from her phone app just before 2:30 a.m. on the night she went missing.

The players

Nancy Guthrie

An 84-year-old woman who went missing from her home in Tucson, Arizona on January 31, 2026. Guthrie is the mother of 'TODAY' show anchor Savannah Guthrie.

Maureen O'Connell

A former FBI special agent who provided insight on the use of 'signal sniffer' technology in the search for Nancy Guthrie.

Chris Nanos

The Pima County Sheriff who said the department is 'just tracking down leads' in the disappearance of Nancy Guthrie.

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What they’re saying

“With regards to this particular tool … I do know that the pacemaker sends off a very short-distance alert, or whatever, so they're going to have to get really close.”

— Maureen O'Connell, Former FBI Special Agent (NewsNation)

What’s next

The Pima County Sheriff's Department said it has received nearly 18,000 calls to its tip line, with more than 4,000 coming in the last 24 hours. On Friday, a SWAT operation by the department two miles from Guthrie's home led to three people being detained, though no arrests were made.

The takeaway

The use of advanced technology like the 'signal sniffer' highlights the intense efforts by authorities to locate Nancy Guthrie and determine what happened to the 84-year-old. The disappearance has garnered national attention, and investigators are pursuing all leads in hopes of bringing Guthrie home safely.