The National Office Of Security Enforcement (NOOSE) is an high-end law enforcement organization in Liberty City in Grand Theft Auto IV. It is a consolidation of the Military and SWAT units seen in previous GTA games.
NOOSE is based on the U.S. Department of Homeland Security and is separated into two divisions: the Liberty City Patriotism and Immigration Authority, based on the U.S. Customs and Border Protection, and the Liberty City Tactical Response Unit, based on the NYPD Emergency Service Unit.
NOOSE is called upon to assist the police when the player has a wanted level of at least 3 stars, before the FIB. Patriotism and Immigration Authority officers are largely similar to the LCPD's in behavior, weapons, appearance and mannerisms. Tactical Response officers, however, are designed to appear as fully equipped tactical squad units, with heavy armor and weaponry.
NOOSE's vehicle fleet consists of modified Police Cruisers, Patriots, Enforcers, Annihilators, and Armored Personnel Carriers. The NOOSE Cruisers and Patriots are exclusively driven by Patriotism and Immigration Authority officers, while the Enforcers and the APCs are used solely by the Tactical Response Unit. The Annihilator may appear with occupants from either division, depending on who is pursuing the player on the ground.
- Tactical Response officers are well protected with body armor and don't lose health very quickly. Despite being more resilient to damage, Tactical Response officers are slightly less accurate than FIB Agents.
- NOOSE's primary weapon is the Carbine Rifle. The SMG and the Pump Shotgun serve as secondary weapons, and the Pistol is the standard issue back-up weapon which NOOSE agents will use if their main weapon is shot away. Additionally, the Tactical Response Unit uses the Assault SMG and Auto Shotgun on foot as well as the Advanced Machine Gun from the Annihilator in The Ballad of Gay Tony. In Grand Theft Auto: Chinatown Wars, NOOSE units carry Micro SMG's.
- Agents always use good cover (e.g. behind a car, behind a wall, inside their helicopter).
- Tactical Response officers usually move together as a unit and pursue the player more aggressively than LCPD officers on foot.
- A noose is a type of self-tightening knot, most commonly known for the Hangman's knot used in public hangings. A reference to the Hangman's knot is the one is depicted on the eagle's shield within the NOOSE seal.
- NOOSE's seal is a combination on the seals of the U.S. Department of Homeland Security and the National Security Agency. The color scheme, border, and eagle is based on the DHS seal, and the shield and key the eagle is holding is similar to the NSA seal.
- The player may notice that the insignia of NOOSE on the NOOSE Cruiser and NOOSE Patriot is labeled LC Noose. After the capital "N," the following letters are all lowercase and the second "o" is smaller than a regular lowercase letter. This may be a reference to GTA III's FBI Car, which is poorly written as "Fbi Car".
- Although the APC in TBOGT is labeled "NOOSE Tactcal Response Unit", it is never actually used by the NOOSE, apart from the mission Frosting on the Cake.
- If the player throws a grenade under or near a NOOSE Enforcer it will not even try to move away from that area, which the normal Police cars would do.
- When NOOSE Cruisers chase you the officers inside are wearing LCPD uniforms/insignia instead of NOOSE insignia. This could mean that Liberty City NOOSE is a unit of the LCPD.
- When Annihilators come after you they shout things like "This is the LCPD".
- NOOSE are 'nicer' to the player during car chases due to only 1 person trying to shoot at the back of the players car instead of the FIB's 3 (not 4 because of the driver).