California Code, Welfare and Institutions Code - WIC § 5304

(a) The court shall remand a person named in the petition for postcertification treatment to the custody of the State Department of State Hospitals or to a licensed health facility designated by the county of residence of that person for a further period of intensive treatment, not to exceed 180 days from the date of court judgment, if the court or jury finds that the person named in the petition for postcertification treatment has done any of the following:

(b) The person shall be released from involuntary treatment at the expiration of 180 days unless the public officer, pursuant to Section 5114, files a new petition for postcertification treatment on the grounds that he or she has attempted, inflicted, or made a serious threat of substantial physical harm upon another during his or her period of postcertification treatment, and he or she is a person who by reason of mental health disorder, presents a demonstrated danger of inflicting substantial physical harm upon others.  The new petition for postcertification treatment shall be filed in the superior court in which the original petition for postcertification was filed.

(c) The county from which the person was remanded shall bear any transportation costs incurred pursuant to this section.