Article continues below advertisementNew details are raising eyebrows in the search for Savannah Guthrie's missing mother, Nancy Guthrie.According to a new report, the FBI has been blocked from reviewing critical evidence tied to the case. On Thursday, February 12, Sheriff Chris Nanos reportedly pushed back after the FBI asked the Pima County Sheriff's Department to send physical evidence - including a glove and other DNA - to the bureau's national crime lab in Quantico, Va. Instead, Chris is said to be insisting on using a separate lab in Florida as the search for Nancy, 84, continues.