What is the test for obtaining discovery of a police officer personnel file?

To obtain discovery of officer personnel files, a defendant must "file a motion supported by affidavits showing 'good cause for the discovery,' first by demonstrating the materiality of the information to the pending litigation, and second by 'stating upon reasonable belief' that the police agency has the records or information at issue." (Warrick v. Superior Court (2005) 35 Cal.4th 1011, 1019 (Warrick).) This two-part showing is a " 'relatively low threshold for discovery.' " (Ibid.)