<Tr> <Th_colspan="2"> Website </Th> </Tr> <Tr> <Td_colspan="2"> www.ncis.navy.mil </Td> </Tr> <P> The United States Naval Criminal Investigative Service (NCIS) is the primary law enforcement agency of the U.S. Department of the Navy . Its primary function is to investigate criminal activities involving the U.S. Navy and U.S. Marine Corps, though its broad mandate includes national security, counterintelligence, counter-terrorism, cyber warfare, and the protection of U.S. naval assets worldwide . NCIS is the successor organization to the former Naval Investigative Service (NIS), which was established by the Office of Naval Intelligence after the Second World War . </P> <P> The vast majority of NCIS personnel are civilian, roughly half of whom are special agents trained to carry out a wide variety of assignments around the world . NCIS agents are armed federal law enforcement investigators, who frequently coordinate with other U.S. government agencies and have a presence in over 40 countries, as well as on U.S. Navy vessels . NCIS special agents are supported by analysts and other experts skilled in disciplines such as forensics, surveillance, surveillance countermeasures, computer investigations, physical security, and polygraph examinations . </P>

What does the naval criminal investigative service do