Fox News' David Spunt reports on the search for Nancy Guthrie, now in its third week. 'America's Most Wanted' co-host Callahan Walsh details the FBI and local law enforcement's use of high-tech tools, including a helicopter scanner to help detect her pacemaker. #fox #media #breakingnews #us #usa #new #news #breaking #foxnews #nancyguthrie #guthrie #savannahguthrie #tucson #arizona #missingperson #abduction #kidnapping #crime #crimenews #crimestory #police #fbi #today #todayshow #technology #