Cal. HSC § 1798.6

(a) Authority for patient health care management in an emergency shall be vested in that licensed or certified health care professional, which may include any paramedic or other prehospital emergency personnel, at the scene of the emergency who is most medically qualified specific to the provision of rendering emergency medical care. If no licensed or certified health care professional is available, the authority shall be vested in the most appropriate medically qualified representative of public safety agencies who may have responded to the scene of the emergency.

(b) If any county desires to establish a unified command structure for patient management at the scene of an emergency within that county, a committee may be established in that county comprised of representatives of the agency responsible for county emergency medical services, the county sheriff’s department, the California Highway Patrol, public prehospital-care provider agencies serving the county, and public fire, police, and other affected emergency service agencies within the county. The membership and duties of the committee shall be established by an agreement for the joint exercise of powers under Chapter 5 (commencing with Section 6500) of Division 7 of Title 1 of the Government Code.

(c) Notwithstanding subdivision (a), authority for the management of the scene of an emergency shall be vested in the appropriate public safety agency having primary investigative authority. The scene of an emergency shall be managed in a manner designed to minimize the risk of death or health impairment to the patient and to other persons who may be exposed to the risks as a result of the emergency condition, and priority shall be placed upon the interests of those persons exposed to the more serious and immediate risks to life and health. Public safety officials shall consult emergency medical services personnel or other authoritative health care professionals at the scene in the determination of relevant risks.