California Code, Welfare and Institutions Code - WIC § 4139

(a) Except as otherwise authorized by law, or when authorized by the director of the state hospital, and except as provided in subdivision (b), a person who possesses with the intent to deliver, or delivers, to a patient in a state hospital listed in Section 4100 any item listed in paragraphs (1) to (3), inclusive, that has been prohibited for possession by a patient either by statute or by regulation is guilty of a misdemeanor, punishable by a fine not to exceed one thousand dollars ($1,000) for each item.

(b) If a person visiting a patient in a state hospital listed in Section 4100, upon being searched or subjected to a metal detector, is found to be in possession of an item prohibited for patient possession pursuant to subdivision (a), the item shall be subject to confiscation but shall be returned on the same day the person visits the patient, unless the item is held as evidence in a case where the person is cited for a violation of subdivision (a). If, upon investigation, it is determined that no prosecution will take place, the item shall be returned to the owner at the owner's expense. Notice of this provision shall be posted in all areas where visitors are searched prior to visitation with a patient and outside the facility in a location easily visible to visitors so that they can leave prohibited items in their cars before entering the visitor area.