
Quoting
Branson v. Martin (1997) 56 Cal.App.4th 300, 306
Under Penal Code section 808, all judges of the Supreme Court, Courts of Appeal, superior courts, municipal courts and justice courts are automatically deemed to be "magistrates." By its wording, Penal Code section 808 does not make that an exclusive list. It does not say that other judicial officers cannot be magistrates.
Penal Code section 807 defines a magistrate as "an officer having power to issue a warrant for the arrest of a person charged with a public offense." Government Code sections 72190.1 and 72190.2 specifically provide that, if assigned the task by the presiding judge, a commissioner may conduct arraignments and may issue and sign bench warrants. Thus, under those sections, if, on the initial date of appellant's court appearance, Commissioner Martin had the general power to conduct traffic infraction arraignments and to issue bench warrants, Commissioner Martin qualified as a magistrate.