California Code, Business and Professions Code - BPC § 828

If the licensing agency determines, pursuant to proceedings conducted under Section 820, that there is insufficient evidence to bring an action against the licentiate pursuant to Section 822, then all licensing agency records of the proceedings, including the order for the examination, investigative reports, if any, and the report of the physicians and surgeons or psychologists, shall be kept confidential and are not subject to discovery or subpoena. If no further proceedings are conducted to determine the licentiates  1 fitness to practice during a period of five years from the date of the determination by the licensing agency of the proceeding pursuant to Section 820, then the licensing agency shall purge and destroy all records pertaining to the proceedings. If new proceedings are instituted during the five-year period against the licentiate by the licensing agency, the records, including the report of the physicians and surgeons or psychologists, may be used in the proceedings and shall be available to the respondent pursuant to the provisions of Section 11507.6 of the Government Code.