What is the test for admitting an official report without requiring a witness to testify as to their trustworthiness?

"Whether the trustworthiness requirement has been met is a matter within the trial court's discretion." (People v. Parker (1992) 8 Cal.App.4th 110, 116.) Evidence Code section 1280 " 'permits the court to admit an official record or report without necessarily requiring a witness to testify as to its identity and mode of preparation if the court takes judicial notice or if sufficient independent evidence shows that the record or report was prepared in such a manner as to assure its trustworthiness.' [Citation.] 'In addition to taking judicial notice, a court may rely on the rebuttable presumption that official duty has been regularly performed (Evid. Code, 664) as a basis for finding that the foundational requirements of Evidence Code section 1280 are met.' [Citation.]" (People v. George (1994) 30 Cal.App.4th 262, 274.)