The mysterious disappearance of “Today” show host Savannah Guthrie’s elderly mother in Arizona is officially being investigated as a crime, law enforcement officials confirmed — after the 84-year-old vanished from her home on Saturday. Nancy Guthrie, the mother of the NBC anchor, was last seen Saturday around 9:30 p.m. near her residence in the Catalina Foothills area near Tucson, where officials found a “very concerning” scene, Pima County Sheriff Chris Nanos said at a press conference Monday.