The board of selectmen shall appoint an administrative officer for an indefinite term and fix his compensation within the amount appropriated by the town. The administrative officer shall be appointed on the basis of his executive and administrative qualifications. He shall be a person especially fitted by education, training or previous experience in public administration to perform the duties of the office. He need not be a resident of the town or of the commonwealth at the time of his appointment, but he must establish residence within the town within 12 months following his appointment. He shall not have served in an elective office in the town government for at least three years prior to his appointment. He shall devote full time to the office and shall not hold any other public office, elective or appointive, nor engage in any other business or occupation during his term, unless such action is approved in writing by the board of selectmen. The town may from time to time by bylaw establish such additional qualifications as seem necessary and appropriate.
Any vacancy in the office of the administrative officer shall be filled as soon as possible by the selectmen, and meanwhile they shall appoint a suitable person as temporary administrative officer to perform the duties of the office. Such temporary appointment may not exceed three months, but one additional renewal may be voted not to exceed a second three months. Compensation for such person shall be set by the board of selectmen.