Cal. Welf. and Inst. Code § 5276.1
The person requesting release may, upon advice of counsel, waive the presence at the evidentiary hearing of the physician, licensed psychologist who meets the requirements of the first paragraph of Section 5251, or other professional person who certified the petition under Section 5251 and of the physician, or licensed psychologist who meets the requirements of the second paragraph of Section 5251, providing intensive treatment. In the event of such a waiver, such physician, licensed psychologist, or other professional person shall not be required to be present at the hearing if it is stipulated that the certification and records of such physicians, licensed psychologists, or other professional persons concerning the mental condition and treatment of the person regarding release will be received in evidence.
Ca. Welf. and Inst. Code § 5276.1