Me. Stat. tit. 15 § 1466
If a person confined in a penal institution in any other state may be a material witness in a criminal action pending in a court of record or in a grand jury investigation in this State, a judge of the court may certify that there is a criminal proceeding or investigation by a grand jury or a criminal action pending in the court, that a person who is confined in a penal institution in the other state may be a material witness in the proceeding, investigation or action, and that the person's presence will be required during a specified time. The certificate must be presented to a judge of a court of record in the other state having jurisdiction over the prisoner confined, and a notice must be given to the attorney general of the state in which the prisoner is confined. [1967, c. 317(NEW).]
15 M.R.S. § 1466