Section 301.29 - Bonds of employees; police powers; investigation of complaints(2) The superintendents of all the state correctional institutions, and the employees under them to whom they delegate police power, may arrest any person within or upon the grounds of the institutions whom they have reason to believe guilty of any offense against the laws or regulations governing the institutions; and for that purpose they shall possess the powers of constables.(3) The department shall investigate complaints against any institution under its jurisdiction or against the officers or employees of the institutions. For that purpose, the secretary and such officers and employees as the secretary authorizes may summon and swear witnesses, take testimony and compel the production of books and papers. On its own initiative, the department may investigate the affairs of any institution. Any written communication or complaint addressed to the secretary by any inmate, employee or subordinate of an institution shall be immediately forwarded unopened to the addressee.