NCIS stands for Naval Criminal Investigative Service. It is the primary investigative law enforcement agency of the United States Department of the Navy. NCIS is responsible for investigating major criminal activities involving the U.S. Navy and Marine Corps, as well as national security, counterintelligence, counterterrorism, and cyberwarfare matters. NCIS agents are armed federal law enforcement officers who work worldwide in various capacities related to naval security and criminal investigations.
