Me. Rev. Stat. tit. 30-A, § 1502

When a vacancy occurs in the office of sheriff, the jailer lawfully acting continues in office and shall retain charge of the jail and of all prisoners in or committed to the jail. The jailer's official neglects and misdoings are a breach of the principal's official bond until a new sheriff is qualified, or the Governor removes that jailer and appoints another, which the Governor may do. The jailer so appointed shall give bond in the manner required of a sheriff for the faithful discharge of duties.