(2) The person of an adult in custody sentenced to imprisonment in the Department of Corrections institution is under the protection of the law and the adult in custody shall not be injured except as authorized by law. [Amended by 1953 c.476 §5; 1969 c.502 §9; 1987 c.158 §75; 1987 c.320 §165; 2019 c.213 §65]