California Code, Welfare and Institutions Code - WIC § 301

The director of community services or his designee shall have the power to direct the removal of any person, within his jurisdiction, to a hospital approved by the commissioner pursuant to subdivision (a) of section 9.39 of this article if the parent, spouse, or child of the person, a licensed physician, health officer, peace officer or police officer reports to him that such person has a mental illness for which immediate care and treatment in a hospital is appropriate and which is likely to result in serious harm to himself or others, as defined in section 9.39 of this article.  It shall be the duty of peace officers, when acting pursuant to their special duties, or police officers, who are members of an authorized police department or force or of a sheriff's department to assist representatives of such director to take into custody and transport any such person.  Upon the request of a director of community services or his designee an ambulance service, as defined in subdivision two of section three thousand one of the public health law, is authorized to transport any such person.  Such person may then be retained pursuant to the provisions of section 9.39 of this article.