Iowa Code Title III. Public Services and Regulation [Chs. 80-122C] § 80.22. Prohibition on other departments

All other departments and bureaus of the state are hereby prohibited from employing special peace officers or conferring upon regular employees any police powers to enforce provisions of the statutes which are specifically reserved by 1939 Iowa Acts, ch. 120, to the department of public safety. But the commissioner of public safety shall, upon the requisition of the attorney general, from time to time assign for service in the department of justice such of its officers, not to exceed six in number, as may be requisitioned by the attorney general for special service in the department of justice, and when so assigned such officers shall be under the exclusive direction and control of the attorney general.