The Arizona police department is flying over the Tucson, Ariz., desert with a Bluetooth signal detector to detect a signal ...

They’re searching for Nancy Guthrie’s heartbeat. Cops are flying over the Tucson desert with a high-tech Bluetooth signal detector, also known as a signal sniffer, in an attempt to locate a signal ...

Investigators in Nancy Guthrie's disappearance are using a device called a "signal sniffer" to try to detect transmissions ...

Investigators are using signal sniffer to try to detect Nancy Guthrie's pacemaker.

A device to detect emissions from Nancy Guthrie's pacemaker is among the tools investigators are using as their search for ...