The award-winning team behind long-running newsmagazine "48 Hours" provides viewers with an unprecedented look into some of the biggest cases handled by the United States Naval Criminal Investigative Service -- which recently celebrated 50 years of inspecting felony crimes, preventing terrorism, and protecting secrets for the Marine Corps and Navy. Agents who have participated in significant investigations with the agency reveal the steps they take to track killers, break fraud cases and hunt terrorists using street smarts and technology. "NCIS" star Rocky Carroll narrates.