Massachusetts District Court: Criminal Model Jury Instructions
MA II. DEFENSE OF ANOTHER
Society wishes to encourage all of us to come to the aid of each other when that is necessary. Therefore, a person may use reasonable force when that is necessary to help another person, if it reasonably appears that the person being aided is in a situation where the law would allow him to act in self-defense himself.
If there is any evidence in this case that the defendant may have been coming to the aid of another person, you must find the defendant not guilty unless the Commonwealth proves beyond a reasonable doubt at least one of the following two things:
First: That a reasonable person in the defendant’s position would not have believed that his (her) use of force was necessary in order to protect [third party] ; or
Second: That to a reasonable person in the defendant’s position would not have believed that [third party] was justified in using such force in his (her) own self-defense.