Cal. Gov. Code § 11189
In any matter pending before a department head, the department head may cause the deposition of persons residing within or without the state to be taken by causing a petition to be filed in the Superior Court in the County of Sacramento reciting the nature of the matter pending, the name and residence of the person whose testimony is desired, and asking that an order be made requiring the person to appear and testify before an officer named in the petition for that purpose. Upon the filing of the petition the court may make an order requiring the person to appear and testify in the manner prescribed by law for like depositions in civil actions in the superior courts of this state under Title 4 (commencing with Section 2016.010) of Part 4 of the Code of Civil Procedure. In the same manner the superior courts may compel the attendance of persons as witnesses, and the production of papers, books, accounts, and documents, under Chapter 2 (commencing with Section 1985) of Title 3 of Part 4 of the Code of Civil Procedure, and may punish for contempt.
Ca. Gov. Code § 11189