Me. Stat. tit. 30-A § 462
Except as otherwise provided by county charter or ordinance, the county commissioners may authorize the sheriff or other designee to request other counties to provide law enforcement officers to assist the requesting county. The county commissioner may authorize the sheriff or other designee to provide law enforcement officers to assist other counties when so requested by a properly authorized sheriff or other designee of the requesting county. [2013, c. 261, §1(NEW).]
The authorizations of the county commissioners under this section must be accompanied by an agreement between the requesting county and the responding county that specifies which county is liable, if any liability is determined to exist, for personal injury or property damage caused by or occurring to the law enforcement officers of the responding county in the course of assisting the requesting county. [2013, c. 261, §1(NEW).]
If a request for assistance is for a major unplanned incident that jeopardizes the health and welfare of the citizens of the requesting county and when delay may cause further jeopardy to life or property or in the case of jointly planned collaborative activity, the sheriff or the sheriff's designee may request assistance from or provide assistance to another county or law enforcement agency whether or not an agreement between the 2 counties or parties exists. Each law enforcement department shall assume its own liability to a 3rd party, except for liability incurred by the command or operational decisions made by the requesting department, which must be assumed by the requesting department. For the purposes of this paragraph, "major unplanned incident" means an extraordinary emergency to which a law enforcement agency is unable to adequately respond that presents a substantial and imminent danger to the public safety and that necessitates the cooperation or assistance of other law enforcement agencies. [2013, c. 261, §1(NEW).]
The law enforcement officers of the responding county or law enforcement agency have the same authority as law enforcement officers within the limits of the requesting county, except as to the service of civil process and, when assisting the other county, have the same privileges and immunities as when acting within their own jurisdiction. [2013, c. 261, §1(NEW).]
30-A M.R.S. § 462