RSA 627:4 Physical Force in Defense of a Person.

I. A person is justified in using non-deadly force upon another person in order to defend himself or a third person from what he reasonably believes to be the imminent use of unlawful, non-deadly force by such other person, and he may use a degree of such force which he reasonably believes to be necessary for such purpose. However, such force is not justifiable if:
(a) With a purpose to cause physical harm to another person, he provoked the use of unlawful, non-deadly force by such other person; or
(b) He was the initial aggressor, unless after such aggression he withdraws from the encounter and effectively communicates to such other person his intent to do so, but the latter notwithstanding continues the use or threat of unlawful, non-deadly force; or
(c) The forc