405 ILCS 5/5-102
Persons who are not residents of this State may not be detained in any facility unless admitted thereto in accordance with the laws of this State, or of the state having jurisdiction of such persons.
A person who is not a resident of this State and who is admitted to a Department facility for services may be returned by the Department to the state of which he is a resident, but no such person may be returned unless arrangements to receive him have been made in the state to which he is to be returned.
The Department, subject to the approval of the Attorney General, may enter into reciprocal agreements with corresponding agencies of other states regarding the interstate transportation or transfer of recipients and may arrange with the proper officials for the acceptance, transfer and support of persons who are residents of this State but who are temporarily detained or who are receiving services in public facilities of other states in accordance with the terms of such agreements. In the case of persons brought to this State under any agreements authorized under this Section, local peace officers may upon request of the Department receive and arrange for admission of such persons pursuant to this Act.
405 ILCS 5/5-102