Cal. Health and Safety Code § 13107

(a) The State Fire Marshal shall investigate every explosion or fire occurring in any state institution, state-owned building, or any building which is determined, pursuant to regulations adopted by the State Fire Marshal, to be state occupied, and every explosion or fire occurring in those areas of the state not under the jurisdiction of a legally organized fire department or fire protection district or other public entity, including, but not limited to, the state, which provides fire protection in which there is suspicion that the crime of arson or attempted arson has been committed. (b) Upon request of the chief fire official of a legally organized fire department or fire protection district, or the governing body thereof, or upon request of the chief of a police department or the sheriff regarding a fire which occurs in an area where there is no operating arson investigation unit, the State Fire Marshal shall, within the limitation of resources and manpower established for those purposes, investigate any explosion or fire occurring within the jurisdiction of the requesting official in which there is suspicion that the crime of arson or attempted arson has been committed. (c) The State Fire Marshal shall cooperate in the establishment of a program for training fire department personnel in arson investigation and detection. (d) In order to carry out his or her responsibilities and duties pursuant to this section, the State Fire Marshal shall establish an arson investigation unit within his or her office, which shall be staffed with necessary personnel to perform the function for which the unit is established. (e) If there is reason to believe that any fire or explosion investigated by the State Fire Marshal resulted from a crime or that a crime has been committed in connection with it, the State Fire Marshal shall report that fact in writing to the district attorney of the county in which the fire or explosion occurred.