California Code, Evidence Code - EVID § 1562

If the original records would be admissible in evidence if the custodian or other qualified witness had been present and testified to the matters stated in the affidavit, and if the requirements of Section 1271 have been met, the copy of the records is admissible in evidence.  The affidavit is admissible as evidence of the matters stated therein pursuant to Section 1561 and the matters so stated are presumed true.  When more than one person has knowledge of the facts, more than one affidavit may be made.  The presumption established by this section is a presumption affecting the burden of producing evidence.