NCIS agents are armed federal law enforcement investigators, who frequently coordinate with other U.S. government agencies and have a presence in more than 41 countries and on U.S. Navy vessels.

In anticipation of the United States entry into World War I, ONI's responsibilities expanded to include espionage, sabotage, and all manner of information on the U.S. Navy's potential adversaries.

The plan contemplated obtaining information by both overt and covert means, and, in the fall of 1916, the first branch office (a small undercover unit) was established in New York City under the supervision of the ONI.

In early 1926, initiatives were undertaken to organize special groups of volunteer reserve intelligence officers who were envisioned to obtain information on persons and activities that might threaten the naval establishment, as well as provide a cadre of trained personnel in the event of a national emergency.

He was followed by a small handful of civilian special agents who were seeded throughout the naval districts beginning in 1936, although by September 1937 they numbered only 14 nationwide.

[4] In June 1939, President Roosevelt directed that ONI handle the investigation of Navy cases relating to sabotage, espionage, and subversive activities.

Their primary tasks related to personnel security inquiries, sabotage, and espionage cases, investigation of Japanese activities in the United States, and war fraud matters.

Although the Secretary of the Navy extended investigative jurisdiction in 1945, no meaningful expansion of personnel occurred until the Korean conflict when a major buildup of civilian agents took place.

Several significant changes in organization and policy occurred during the 1950s and 1960s, as well as refinements in mission, which culminated in the establishment of the Naval Investigative Service (NIS) in February 1966.

In 1991, NIS was responsible for investigating the Tailhook scandal, which involved allegations of sexual misconduct and harassment by Naval and Marine Corps officers in Las Vegas, Nevada.

As a result of the investigation into the Tailhook scandal, the Pentagon's inspector general was sharply critical of NIS leadership, stating that there was a top-down culture showing a lack of cooperation with other authorities in the Navy.

[5] By 1992, Acting Secretary of the Navy, Sean O'Keefe, recommended the word "Criminal" be included in NIS's name to make clear their investigative function.

Current missions for NCIS include criminal investigations, force protection, cross-border drug enforcement, counterterrorism, major procurement fraud, computer crime and counter-intelligence.

[10] On February 14, 2010, Mark D. Clookie became the fourth civilian director of NCIS, having been appointed to the position by Secretary of the Navy Ray Mabus.

[14][15] On June 4, 2019, Omar R. Lopez became the sixth civilian director of NCIS, having been appointed to the position by the Secretary of the Navy, Richard V. Spencer.

These directorates are responsible for outlining the goals and objectives of NCIS relating to their functional area through the Program Direction Document.

The only exception to this is the Contingency Response Field Office, which is headquartered at the Federal Law Enforcement Training Centers at Glynco, Georgia.

[31] The Atlantic Operations Directorate oversees all investigations and operations of NCIS field offices and numerous subordinate elements located throughout the Eastern United States, Europe, Africa, South America, the Middle East, and aboard carrier and expeditionary strike groups based on the East Coast.

[31] The Behavioral Science Group (BSG) supports the NCIS headquarters and field offices on a worldwide basis by deploying licensed psychologists with specialized training and experience in law enforcement psychology and national security.

The BSG consultations provide insight into relevant behavior; optimizing criminal, counterintelligence, and counter-terrorism investigations and operations; and complementing other resources such as analytical and technical expertise.

They perform in a variety of mission support areas in NCIS offices throughout the world, including protective service operations, supply and logistics, communications, administrative duties, intelligence, and security.

[36] The Cyber Directorate has program management oversight of worldwide law enforcement and counterintelligence cyberspace investigations, operations, and digital/multimedia forensics.

[41] The purpose of the program is to provide professional investigative, counterintelligence, and force protection support to deployed Navy and Marine Corps commanders.

It is also the mission of the special agent afloat to offer Navy and Marine Corps leadership advice and operational support on security issues that might threaten the safety of ships, personnel, and resources.

The MTAC is a unique platform in that it merges intelligence from other agencies with information from NCIS source networks and law enforcement activities worldwide to provide the most relevant operational support to the Navy and Marine Corps commanders.

[43] In 2014, in the aftermath of the Washington Navy Yard shooting, NCIS formed the Regional Enforcement Action Capabilities Training (REACT) team.

They respond to death scenes and assist with the investigation of many other high-impact crimes, including sexual and/or aggravated assaults, acts of arson and wrongful destruction, and thefts.

Special agents from all disciplines are trained in additional crime scene processing techniques and are called out on major incidents to search, locate, photograph, document, collect, and preserve physical evidence.

[4] The IG directs the development of NCIS inspection, compliance oversight, and employee misconduct investigative priorities and performance requirements.

[50] All newly hired agents who have not experienced active or reserve duty with the Navy or Marine Corps must also complete the Naval Orientation Correspondence Course.