In a Pitchess hearing, the custodian of records who produces the records and testifies at the in camera hearing must be placed under oath. Appellant, charged with possession of marijuana in jail, sought confidential records of the officer involved. (Pitchess v. Superior Court (1974) 11 Cal.3d 531.) After reviewing the records in camera, the trial court denied the Pitchess motion, and appellant was ultimately convicted and sentenced to prison. On appeal, appellant requested the appellate court independently review the transcripts of the in camera Pitchess hearing. Upon doing so, the court determined that the trial court made a record of the contents of the file presented for review and that it did not abuse its discretion in denying the motion. However, the sealed record also revealed that the court failed to administer the oath to the two custodians of record present, as required by Evidence Code section 710. The custodian of records is obligated to bring to the trial court all “potentially relevant” documents to permit the trial court to examine them for itself. (People v. Mooc (2001) 26 Cal. 4th 1216, 1229.) Administering an oath is necessary to establish the accuracy and veracity of the custodian’s representations regarding the completeness of the records submitted, and to ensure that the “locus” of decision making is with the trial court. Here, the trial court’s finding that documents requested by defendant did not exist was based on the unsworn testimony of one custodian. But unsworn evidence does not constitute testimony and, therefore, the record does not support the court’s finding. Because defendant was not present at the in camera hearing, he cannot be expected to be able to establish prejudice resulting from the failure to administer the oath, and the error is not harmless. The matter was remanded with direction to hold a new Pitchess hearing.