State law authorizes the placement of local law enforcement or security personnel on school campuses through MOUs or partnership agreements.
New Hampshire Revised Statutes Annotated 186:11 Duties of State Board of Education.
XXXVII. School Resource Officers. Require each school district in the state to which a school resource officer is assigned to develop and implement a policy which shall include, at a minimum, a requirement for a signed memorandum of understanding between the school district and the law enforcement agency from which the school resource officer is deployed.