The National Criminal Investigation Service, commonly known as Kripos, is a special agency of the Norwegian Police Service. Based at Bryn in Oslo and established in 1959, it is a national unit that works with organized and serious crime. It both works as an assisting unit for police districts, with special focus on technical and tactical investigation, and is responsible on its own for organized crime. It acts as the center for international police cooperation, including participation in Interpol and Europol. It is subordinate to the National Police Directorate. Kripos represents four percent of the Norwegian police force, with nearly 500 employees.