Cal. Ed. Code § 49078
The service of a lawfully issued subpoena or a court order upon a public school employee solely for the purpose of causing him or her to produce a school record pertaining to any pupil may be complied with by that employee, in lieu of the personal appearance as a witness in the proceeding, by submitting to the court, or other agency, or person designated in the subpoena, at the time and place required by the subpoena or court order, a copy of that record, accompanied by an affidavit certifying that the copy is a true copy of the original record on file in the school or school office. The copy of the record shall be in the form of a photostat, microfilm, microcard, or miniature photograph or other photographic copy or reproduction, or an enlargement thereof.
Ca. Educ. Code § 49078