Article continues below advertisementIn the latest development of Nancy Guthrie's disappearance, the FBI has assisted the Pima County Sheriff's Department in detaining a person for questioning in connection with the abduction of Savannah Guthrie's 84-year-old mother, according to ABC News.A law enforcement official briefed on the investigation informed the outlet an individual was detained during a traffic stop south of Tucson in Rio Rico, Ariz. - near the border with Mexico - noting authorities are preparing to search a location associated with the person being questioned.