Iowa Code § 230.31: Departers from other states.

If a person with mental illness departs without proper authority from a facility in another state and is found in this state, a peace officer in the county in which the patient is found may take and detain the patient without order and shall report the detention to the department who shall provide for the return of the patient to the authorities of the state where the unauthorized leave was made. Pending such return, the patient may be detained temporarily at one of the institutions of this state under the control of the department. Expenses incurred under this section shall be paid in the same manner as is provided for transfers in section 230.8.