California Code, Penal Code - PEN § 2652

It shall be unlawful to use in the prisons, any cruel, corporal or unusual punishment or to inflict any treatment or allow any lack of care whatever which would injure or impair the health of the prisoner, inmate or person confined; and punishment by the use of the strait-jacket, gag, thumb-screw, shower-bath or the tricing up of prisoners, inmates or persons confined is hereby prohibited. Any person who violates the provisions of this section or who aids, abets, or attempts in any way to contribute to the violation of this section shall be guilty of a misdemeanor.