Cal. Welf. and Inst. Code § 1801.5
If a trial is ordered pursuant to Section 1801, the trial shall be by jury unless the right to a jury trial is personally waived by the person, after he or she has been fully advised of the constitutional rights being waived, and by the prosecuting attorney, in which case trial shall be by the court. If the jury is not waived, the court shall cause a jury to be summoned and to be in attendance at a date stated, not less than four days nor more than 30 days from the date of the order for trial, unless the person named in the petition waives time. The court shall submit to the jury, or, at a court trial, the court shall answer, the question: Is the person 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? The court's previous order entered pursuant to Section 1801 shall not be read to the jury, nor alluded to in the trial. The person shall be entitled to all rights guaranteed under the federal and state constitutions in criminal proceedings. A unanimous jury verdict shall be required in any jury trial. As to either a court or a jury trial, the standard of proof shall be that of proof beyond a reasonable doubt.
Ca. Welf. and Inst. Code § 1801.5