COMMISSARIO. — This term designates one of the higher officials of the Sacred Congregation of the Holy Office, who, assisted by two deputies (first and “second compagno”), is chiefly responsible for conducting the preliminary investigation of criminal cases that are to be judged by the Congregation. Both the commissario and the two deputies are chosen from among the religious of the Order of Preachers.
This institution derives from the ancient tribunals of the Inquisition. Pope Pius V served as commissario of the Holy Office from 1551 to 1556 (Pastor, VIII, p. 34).
The term commissario is also used to denote the members of any pontifical commission (v. COMMISSIONI PONTIFICE).