The Crime and Security Branch – previously known as "C3" – is responsible for the administration of national security, counter terrorism and serious crime investigations within the Garda Síochána, the national police force of Ireland. The section oversees intelligence relating to subversive, paramilitary and terrorism matters, conducts counter-intelligence, liaises with foreign law enforcement agencies, handles confidential informants, administers VIP and witness protection, monitors potential corrupt Garda officers and provides information on threats to the state to the Garda Commissioner and Government of Ireland.The Crime & Security Branch comprises a number of Garda units, which it collects information from and issues directives to. The Garda CSB is based at Garda Headquarters in the Phoenix Park, Dublin. It is headed by the Assistant commissioner in charge of Crime and Security, and is staffed mainly by senior officers and intelligence analysts. The branch is responsible for up to 500 Garda officers in other units, who are mainly detectives with investigative duties. CSB maintain the National Intelligence Database, which collates intelligence received from all its sources, and is linked to that of G2.