Me. Stat. tit. 30-A § 2674
Except as otherwise provided by municipal charter or ordinance, the municipal officers may authorize the chief of police or other designee to request other municipalities to provide law enforcement officers to assist the requesting municipality. The county commissioners may authorize the sheriff or other designee to request a municipality to provide law enforcement officers to assist the requesting county. The municipal officers may authorize the chief of police or other designee to provide law enforcement officers to assist other municipalities or counties when so requested by a properly authorized chief of police, sheriff or other designee of the requesting municipality or county. [2013, c. 261, §2(AMD).]
The authorizations of the municipal officers or county commissioners must be accompanied by an agreement between the requesting municipality or county and the responding municipality or county that specifies which governmental entity 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 municipality or county in the course of assisting the requesting municipality or county. [2013, c. 261, §2(AMD).]
If the request for assistance is for a major unplanned incident that jeopardizes the health and welfare of the citizens of the requesting municipality or county and when delay may cause further jeopardy to life or property or in the case of jointly planned collaborative activity, the police chief of any municipality or sheriff of any county or the chief's or sheriff's designee may request assistance from or provide assistance to another municipality or law enforcement agency whether or not an agreement between the 2 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, §2(AMD).]
The law enforcement officers of the responding municipality or county or law enforcement agency have the same authority as law enforcement officers within the limits of the requesting municipality or county, except as to the service of civil process, and, when assisting other municipalities, have the same privileges and immunities as when acting within their own jurisdiction. [2013, c. 261, §2(AMD).]
Notwithstanding section 501 and except as otherwise provided by municipal charter or ordinance, the municipal officers may authorize the chief of police or other designee to request a county sheriff to appoint as a deputy sheriff a municipal law enforcement officer who has satisfied the training requirements of Title 25, sections 2804-C and 2804-E. The authorization of the municipal officers must be accompanied by an agreement between the requesting municipality and the respective county that specifies the purpose and time period for which the authorization is granted and which governmental entity is liable, if any liability is determined to exist, for personal injury or property damage caused by or occurring to law enforcement officers of the municipality in the course of exercising their authority as deputy sheriffs. A municipal law enforcement officer appointed pursuant to this paragraph has the same authority as a deputy sheriff within the respective county, except as to the service of civil process, and has the same privileges and immunities as when acting within the officers own jurisdiction. [2015, c. 419, §1(NEW).]
30-A M.R.S. § 2674