California Code, Military and Veterans Code - MVC § 163.1

All records of any special proceedings of any board of inquiry convened by the commanding general of the state military forces to investigate the causes of any accidents involving National Guard aircraft, the purpose of which investigation is prevention of future accidents, shall not be admissible for any purpose in evidence in any court of this state.

Whenever any such accident involves property damage or personal injury, a collateral investigation shall be conducted to ascertain the causes of such accidents and the records of any collateral investigations shall be discoverable under the appropriate sections of the Code of Civil Procedure.