What is the test for a motion to compel discovery of confidential materials in a peace officer personnel file?

To compel discovery of confidential materials in peace officer personnel files, a defendant must file an affidavit that establishes good cause in the form of a reasonable belief that the type of records requested are material to his or her defense and in the possession of the employing agency; only a relatively low threshold is necessary to compel discovery. (Warrick v. Superior Court (2005) 35 Cal.4th 1011, 1019.) Upon a finding of good cause, the trial court must then review the records in camera and disclose "only that information falling within the statutorily defined standards of relevance." (Id. at p. 1019.)

Fundamental to the procedure under the statutory scheme which codifies Pitchess is "the intervention of a neutral trial judge" to examine the records and determine what documents, if any, should be disclosed. (People v. Mooc (2001) 26 Cal.4th 1216, 1227 (Mooc).) "Documents clearly irrelevant to a defendant's Pitchess request need not be presented to the trial court for in camera review"; however, the "custodian should be prepared to state in chambers and for the record what other documents (or category of documents) not presented to the court were included in the complete personnel record, and why those were deemed irrelevant or otherwise nonresponsive to the defendant's Pitchess motion." (Id. at p. 1229.)