Signal sniffer to detect Nancy Guthrie’s pacemaker deployed, law enforcement sources say

A device to detect emissions from Nancy Guthrie’s pacemaker is among the tools investigators are using as their search for her continues into its third week, law enforcement sources told CBS News.

The high-tech tracking tool, called a “signal sniffer,” has been mounted on a helicopter and may help detectives pinpoint her location, the sources said. Signal sniffers are often used in missing person cases because they can detect low-power electronic signals, such as those emitted by a pacemaker.