The Beretta M12 is a 9×19mm Parabellum caliber submachine gun designed by Beretta. Production started in 1959, the first users were the Italian Carabinieri, Italian State Police and the Guardia di Finanza, though in limited numbers; it was only widely issued beginning in 1978, replacing the old Beretta MAB. In 1962 the Italian Army bought a limited number of Franchi LF-57 submachine guns, judged better than the M12 but never issued to the troops, and only in 1992 the M12S2 variant was introduced, in very limited numbers. The Italian Air Force bought instead many M12S and M12S2 for the airport security units. However, the weapon had a higher initial success in the Arab countries and South America.

The Polizia Penitenziaria, formally the Corpo di Polizia Penitenziaria, is a law enforcement agency in Italy which is subordinate to the Italian Ministry of Justice and operates the Italian prison system as corrections officers. Vatican City, an independent state, does not have a prison system, so the Vatican sends convicted criminals to the Italian prison system.