Reasonable force can best be described as the level of force proportionate to the level of unlawful force about to be utilized against the victim. If someone were to push or slap you, you would most likely not be justified in using a baseball bat or gun as a means of protecting yourself. This level of force (bat or gun) would be considered unreasonable and excessive under the law when compared to a push or a slap in the face. Using excessive force to defend yourself could result in criminal charges leading to your imprisonment and/or the payment of large fines. The line between reasonable force and excessive force is very thin where no buffer zone exists. In addition to using reasonable force, you must be a reluctant participant in the altercation and have attempted to withdraw or retreat (if safe to do so), otherwise, your involvement may be considered to be willing mutual combat (brawling/fighting) and subsequently you may erode any legal protection afforded you under the law.
Minnesota statute 609.065 specifically covers the justifiable taking of human life. The statute specifically states:
"The intentional taking of the life of another is not authorized by section 609.06, except when necessary in resisting or preventing an offense which the actor reasonably believes exposes the actor or another to great bodily harm or death, or preventing the commission of a felony in the actor's place of abode."
Outside of your place of abode, you may only use deadly force in self-defense if you believe the threat of death or great bodily harm exists to you or another and you or the person you are protecting are innocent and reluctant participants in the deadly threat encounter.
Essentially, you cannot provoke someone, shoot them and claim self-defense (you were part of the problem). Additionally, if you rob a bank and are confronted by someone with a gun and you shoot them, you cannot claim self-defense because you are not innocent (you committed a crime by robbing a bank and forfeit your right to self-defense).
Minnesota statute defines “great bodily harm” as:
“…bodily injury which creates a high probability of death, or which causes serious permanent disfigurement, or which causes a permanent or protracted loss or impairment of the function of any bodily member or organ or other serious bodily harm.” (609.02)
Statute 609.065 also states,
“…the actor reasonably believes exposes the actor or another to great bodily harm or death... “.
AOJ-P is short for Ability, Opportunity, Jeopardy and Preclusion. If a threat passes these criterions, the use of deadly force is generally authorized.