California Code, Welfare and Institutions Code - WIC § 1801

(a) If a petition is filed with the court for an order as provided in Section 1800 and, upon review, the court determines that the petition, on its face, supports a finding of probable cause, the court shall order that a hearing be held pursuant to subdivision (b). The court shall notify the person whose liberty is involved and, if the person is a minor, his or her parent or guardian (if that person can be reached, and, if not, the court shall appoint a person to act in the place of the parent or guardian) of the hearing, and shall afford the person an opportunity to appear at the hearing with the aid of counsel and the right to cross-examine experts or other witnesses upon whose information, opinion, or testimony the petition is based. The court shall inform the person named in the petition of his or her right of process to compel attendance of relevant witnesses and the production of relevant evidence. When the person is unable to provide his or her own counsel, the court shall appoint counsel to represent him or her.

The probable cause hearing shall be held within 10 calendar days after the date the order is issued pursuant to this subdivision unless the person named in the petition waives this time.

(b) At the probable cause hearing, the court shall receive evidence and determine whether there is probable cause to believe that discharge of the person would be physically dangerous to the public because of his or her mental or physical deficiency, disorder, or abnormality which causes the person to have serious difficulty controlling his or her dangerous behavior. If the court determines there is not probable cause, the court shall dismiss the petition and the person shall be discharged from the control of the authority at the time required by Section 1766, 1769, 1770, 1770.1, or 1771, as applicable. If the court determines there is probable cause, the court shall order that a trial be conducted to determine whether the person is physically dangerous to the public because of his or her mental or physical deficiency, disorder, or abnormality.