There are various broad or narrow definitions depending on whether benefits or powers are involved.
The one you probably want is that used to describe who can
carry without a permit. That is section 626.84, subd. 1 (c).
Quote:
(c) "Peace officer" means:
(1) an employee or an elected or appointed official of a political subdivision or law enforcement agency who is licensed by the board, charged with the prevention and detection of crime and the enforcement of the general criminal laws of the state and who has the full power of arrest, and shall also include the Minnesota State Patrol, agents of the Division of Alcohol and Gambling Enforcement, state conservation officers, Metropolitan Transit police officers, Department of Corrections' Fugitive Apprehension Unit officers, and Department of Commerce Insurance Fraud Unit officers; and
(2) a peace officer who is employed by a law enforcement agency of a federally recognized tribe, as defined in United States Code, title 25, section 450b(e), and who is licensed by the board.