From Fox News. Investigators have reportedly contacted Mexican authorities and are using advanced DNA technology as a mysterious donor added $100,000 to the reward in the search for Nancy Guthrie. #fox #media #breakingnews #us #usa #new #news #breaking #foxnews #crime #crimenews #crimestory #criminal #police #investigation #dnatechnology #forensics #genetics #genealogy #reward #search #missing #nancyguthrie #mexico #international…