Investigators in Nancy Guthrie's search using a "signal sniffer", tracking new clues
Nancy Guthrie, the 84-year-old mother of "Today" show co-host Savannah Guthrie, was reported missing when she failed to show up for church on Feb. 1, after vanishing in the middle of the night from her home in Tucson, Arizona, in an apparent abduction. Authorities said Guthrie's pacemaker was disconnected from the pacemaker app on her cellphone at 2:28 a.m.