Law enforcement in Hungary is split among the police and the National Tax and Customs Administration. The Hungarian Police is the main and largest state law enforcement agency in Hungary. It carries nearly all general police duties such as criminal investigation, patrol activity, traffic policing, border control. It is led by the National Police Commissioner under the control of the Minister of the Interior. The body is divided into county police departments which are also divided into regional and town police departments. The National Police also have subordinate agencies with nationwide jurisdiction, such as the "Nemzeti Nyomozó Iroda" (National Bureau of Investigation), a civilian police force specialised in investigating serious crimes, and the gendarmerie-like, militarised "Készenléti Rendőrség" (Stand-by Police) mainly dealing with riots and often reinforcing local police forces. Due to Hungary's accession to the Schengen Treaty, the Police and Border Guards were merged into a single national corps, with the Border Guards becoming Police Officers. This merger took place in January 2008. The Customs and Excise Authority remained subject to the Ministry of Finance under the National Tax and Customs Administration.