"Today" show host Savannah Guthrie released a new video on social media Monday, imploring her mother's captor to "do the right thing" and help her family find her. It has been nearly six months since the abduction of 84-year-old Nancy Guthrie, who was taken from her Tucson, Arizona, home in the middle of the night. ABC News’ Aaron Katersky has the latest. #nancyguthrie #savannahguthrie #tucson #arizona #news #abcnews