India, Feb. 15 -- Amid the search for Nancy Guthrie, the mother of 'Today' show host Savannah Guthrie, NewsNation's Brian Entin has reported that investigators are using a "signal sniffer" in an attempt to detect Nancy's pacemaker. Pima County Sheriff Chris Nanos told Fox News that no arrests have been made in the case yet.

"Investigators have used what is called a "signal sniffer." It is a small device that was sent in and attached to the Sheriff's helicopter. It can detect Nancy Guthrie's pacemaker signal. The helicopter has to stay low and move slowly for it to work," Entin wrote on X.

As the search entered its third week on Sunday, February 14, a task force waited for forensic results from a late-night operation that took place on F...