Nancy Guthrie Latest: Investigator Announces 'Good Lead'

The search for Nancy Guthrie is now in its fifth week, as authorities continue to sift through leads and explore new avenues in an attempt to locate the 84-year-old mother of Today cohost Savannah Guthrie.

Nancy Guthrie disappeared from her residence in Tucson, Arizona in the early morning hours of Feb. 1. New surveillance video, taken between midnight and 6 a.m. outside a house roughly 2.5 miles from Guthrie's, shows several cars driving through, including around the time the missing woman's pacemaker last synced.