Iowa Code § 29B.12: Punishment prohibited before trial.

Subject to section 29B.58, no person, while being held for trial or the result of a trial, may be subjected to punishment or penalty other than arrest or confinement upon the charges pending against the person, nor shall the arrest or confinement imposed upon the person be any more rigorous than the circumstances require to insure the person’s presence, but the person may be subjected to minor punishment during that period for infractions of discipline.