Every release on bail with or without security is conditioned upon the defendant‘s good behavior while so released, and upon a showing that the proof is evident or the presumption great that the defendant has committed a felony during the period of release, the defendant’s bail may be revoked, after a hearing, by the magistrate who allowed it or by any judge of the court in which the original charge is pending. Pending such revocation, the defendant may be held without bail by order of the magistrate before whom the defendant is brought after an arrest upon the second charge.