The law is enforced in Norway by the Norwegian Police Service. It is a Unified National Police Service made up of 27 Police Districts and several specialist agencies, such as Norwegian National Authority for the Investigation and Prosecution of Economic and Environmental Crime, known as ''Økokrim''; and the National Criminal Investigation Service, known as ''Kripos'', each headed by a chief of police. The Police Service is headed by the National Police Directorate, which reports to the Ministry of Justice and the Police. The Police Directorate is headed by a National Police Commissioner. The only exception is the Norwegian Police Security Agency, whose head answers directly to the Ministry of Justice and the Police.