Cal. Welfare and Institutions Code § 5150.05

(a) When determining if probable cause exists to take a person into custody, or cause a person to be taken into custody, pursuant to Section 5150, a person who is authorized to take that person, or cause that person to be taken, into custody pursuant to that section shall consider available relevant information about the historical course of the person’s mental disorder if the authorized person determines that the information has a reasonable bearing on the determination as to whether the person is a danger to others or to themselves, or is gravely disabled. (b) For purposes of this section, “information about the historical course of the person’s mental disorder” includes evidence presented by the person who has provided or is providing mental health or related support services to the person subject to a determination described in subdivision (a), evidence presented by one or more members of the family of that person, and evidence presented by the person subject to a determination described in subdivision (a) or anyone designated by that person. (c) If the probable cause in subdivision (a) is based on the statement of a person other than the one authorized to take the person into custody pursuant to Section 5150, a member of the attending staff, or a professional person, the person making the statement shall be liable in a civil action for intentionally giving a statement that they know to be false. (d) This section does not limit the application of Section 5328.