Article continues below advertisementAuthorities may have hit a breakthrough in the case of Savannah Guthrie's missing mom, Nancy Guthrie.According to ABC News, a source claimed the FBI is currently analyzing "potentially critical DNA" found inside the 84-year-old's Tucson, Ariz., home, where she was taken from on February 1.The report revealed a private Florida lab working with the Pima County Sheriff's Department sent over the DNA sample recently. Personnel are using advanced technology to try and identify the DNA that may belong to the kidnappers.