The national authority for public order and security in Italy is the Ministry of Interior. It has command over the four principal police forces which operate throughout the country, exercising its authority over them through its Department of Public Security (DPS).

The DPS is headed by the “Chief of Police – Director General of Public Security” who is appointed by the President of the Italian Republic upon recommendation of the Ministry of Interior.

The DPS is in charge of coordinating law enforcement action by the national police forces. Their investigations are coordinated through the Public Prosecutor’s Office, and each one sits structurally in a different Ministry:

Polizia di Stato (Ministry of Interior): serving as the state police, this national police force is part of DPS. Its responsibilities include investigative and law enforcement duties, and the security of motorway, railway, and waterway networks;
Arma dei Carabinieri (Ministry of Defence): a force with military status and nationwide remit for crime investigations. It also serves as the military police for the Italian armed forces and can be called upon for national defence action;
Guardia di Finanza (Ministry of Economy and Finance): a force with military status and nationwide remit for financial crime investigations.