Article continues below advertisementNancy Grace revealed authorities investigating Nancy Guthrie's disappearance are now looking into a "suspicious vehicle" that was seen in the 84-year-old's Tucson, Ariz., neighborhood on the morning of January 31, the last day she was seen.On the Wednesday, March 19, episode of "Crime Stories With Nancy Guthrie" the legal commentator discussed the update with investigative reporter David Mack.