California Code, Penal Code - PEN § 4002

(a) Persons committed on criminal process and detained for trial, persons convicted and under sentence, and persons committed upon civil process, shall not be kept or put in the same room, nor shall male and female prisoners, except spouses, sleep, dress or undress, bathe, or perform eliminatory functions in the same room. However, persons committed on criminal process and detained for trial may be kept or put in the same room with persons convicted and under sentence for the purpose of participating in supervised activities and for the purpose of housing, provided, that the housing occurs as a result of a classification procedure that is based upon objective criteria, including consideration of criminal sophistication, seriousness of crime charged, presence or absence of assaultive behavior, age, and other criteria that will provide for the safety of the prisoners and staff.

(b) Inmates who are held pending civil process under the sexually violent predator laws shall be held in administrative segregation. For purposes of this subdivision, administrative segregation means separate and secure housing that does not involve any deprivation of privileges other than what is necessary to protect the inmates and staff. Consistent with Section 1610, to the extent possible, the person shall continue in his or her course of treatment, if any. An alleged sexually violent predator held pending civil process may waive placement in secure housing by petitioning the court for a waiver. In order to grant the waiver, the court must find that the waiver is voluntary and intelligent, and that granting the waiver would not interfere with any treatment programming for the person requesting the waiver. A person granted a waiver shall be placed with inmates charged with similar offenses or with similar criminal histories, based on the objective criteria set forth in subdivision (a).

(c) Nothing in this section shall be construed to impose any requirement upon a county to confine male and female prisoners in the same or an adjoining facility or impose any duty upon a county to establish or maintain programs which involve the joint participation of male and female prisoners.