“An Arizona sheriff is blocking FBI access to key evidence in the investigation into the abduction of U.S. television journalist Savannah Guthrie's mother, impairing its ability to assist in the probe, a U.S. law enforcement official with knowledge of the case told Reuters on Thursday. The FBI asked Pima County Sheriff Chris Nanos for physical evidence in the case, including a glove and DNA from the home of 84-year-old Nancy Guthrie, to be processed at the FBI's national crime laboratory in Quantico, Virginia, but Nanos has insisted instead on using a private lab in Florida, the official said. Outsourcing forensic...