The attorney general is hereby authorized, subject to the approval of the controller of the department of administration, to enter into contracts with similar officials of any other state or states for the purpose of sharing an equitable portion of the cost of effecting the return of any person who has violated the terms and conditions of parole as imposed by this state. The contract shall covenant and agree as follows:

    “1. The party states hereby agree that any two or more of them may, in the discretion of their appropriate officials, cooperate in effecting the return of any parole violator.

    “2. In any instance where any officer or officers of one or more of the parties hereto shall effect the return of a parole violator from any jurisdiction to the custody of the state directing his return, the state on whose behalf the return is made shall bear the financial burden of such return and the extent of the financial liability of the cooperating states shall be determined as provided in paragraphs 3, 4 and 5 of this contract.

    “3. In every instance where a cooperative return of one or more parole violators is undertaken, the round trip distance which would have been traveled by the officers of each cooperating state in effecting the return of its own violators shall be computed and the sum of all such round trip distances shall also be computed. The share of the expense of a trip chargeable to any cooperating state shall be determined by ascertaining the proportion which its own round trip would have borne to the sum of all round trips which would have been necessary if all states had effected the return of their own violators by employing their own regular officers. Whenever the violator or violators of any cooperating state are not returned to the ultimate destination entirely by the regular officer or officers of another cooperating state or states, the state to which such violator or violators are to be returned shall be entitled to deduct the round trip distance between said ultimate destination and the point where it receives custody of its violator or violators from the round trip distance which its officer or officers would have traveled if such state had effected the entire return of such violator or violators. Standard highway or railway mileage shall be used in calculating distances pursuant to this paragraph.

    “4. The entire cost of a cooperative trip, but not including any charge on account of the salary or wages of any officer employed on said trip, shall form the base for determining the share of the expense to be borne by each cooperating state. The cost of any mileage shall be at the official rate for vehicles prevailing in the state by which such vehicles are owned or leased.

    “5.(a) Except where any injury or damage referred to herein results solely from the violent act or acts of its own violator or violators, no cooperating state shall be chargeable with any cost nor shall such state incur any liability by reason of injury to any officer regularly employed by another cooperating state nor shall any cooperating state be chargeable with or incur any liability by reason of damage to any vehicle or other equipment owned or leased by another cooperating state.

    (b) Workmen’s compensation benefits and payments shall be determined and made in accordance with the laws of the state regularly employing the officer.

    “6. All payments due under this contract shall be made within thirty days of the conclusion of the cooperative trip by reason of which they have accrued unless the parties hereto shall by mutual agreement determine otherwise.”