Six Weeks In, Detectives Persevere in Nancy Guthrie Disappearance

Nancy Guthrie, Savannah Guthrie's mother, remains missing in Tucson six weeks after Jan. 31 as investigators, with the FBI, chase hundreds of leads; DNA from gloves near her home has been ruled out as linked to the abductor, a backpack and an unidentified car are being examined, and no arrests have been made while detectives canvass the neighborhood; Savannah Guthrie has visited the Today show during her hosting hiatus and plans to resume without a timeline.