Cal. Health & Safety Code § 1444.6

If a county hospital requests an ambulance to transfer a mental health patient who is unstable and has a history of being assaultive to another facility, notwithstanding any other provision of law, the director of the hospital or a designee shall inform the ambulance personnel of the instability and potential assaultiveness of the mental health patient. The county hospital shall establish procedures as are necessary to assure that the notification required by this section is given in appropriate cases and to assure that these notifications are documented.