I was just looking into this for myself, so figured I'd share. From an MCLE book, updated October, 2010, dealing with CRIMINAL law only. (Note: I am a lawyer, but the below is for informational/educational purposes only - YMMV):
[h=2]SELF-DEFENSE[/h]A person may use reasonable force when necessary to defend himself or herself from physical harm at the hands of another. Such use of force in self-defense is fully justified and provides a complete defense to criminal charges arising out of the use of such force.
Strictly speaking, self-defense is not a defense at all. When the issue is properly raised, either through the Commonwealths case or through witnesses called by the defense, the Commonwealth has the burden of proving beyond a reasonable doubt that the defendant did not act in self-defense. See Commonwealth v. A Juvenile , 396 Mass. 108, 113-14 (1985). If, at the conclusion of the evidence, the finder of fact has a reasonable doubt as to whether the defendant acted in self-defense, the defendant must be found not guilty.
To prove beyond a reasonable doubt that the defendant did not act in self-defense, the Commonwealth must show that one of the following elements of self-defense is absent from the case:
[h=2]Use of Deadly Force[/h]The use of deadly force in self-defense has additional requirements. Deadly force, which is "force intended or likely to cause death or great bodily harm," Commonwealth v. Klein, 372 Mass. 823, 827 (1977), may be used to repel an attack only under the following circumstances:
The burden remains squarely on the Commonwealth to prove beyond a reasonable doubt that the defendant was not entitled to use deadly force or that the force was excessive. In murder cases, excessive use of deadly force in self-defense is manslaughter.Commonwealth v. Acevedo, 446 Mass. 435, 443 (2006); see also Commonwealth v. Glover, 76 Mass. App. Ct. 799, 804-09 (2010).
[h=2]SELF-DEFENSE[/h]A person may use reasonable force when necessary to defend himself or herself from physical harm at the hands of another. Such use of force in self-defense is fully justified and provides a complete defense to criminal charges arising out of the use of such force.
Strictly speaking, self-defense is not a defense at all. When the issue is properly raised, either through the Commonwealths case or through witnesses called by the defense, the Commonwealth has the burden of proving beyond a reasonable doubt that the defendant did not act in self-defense. See Commonwealth v. A Juvenile , 396 Mass. 108, 113-14 (1985). If, at the conclusion of the evidence, the finder of fact has a reasonable doubt as to whether the defendant acted in self-defense, the defendant must be found not guilty.
To prove beyond a reasonable doubt that the defendant did not act in self-defense, the Commonwealth must show that one of the following elements of self-defense is absent from the case:
- The defendant must have reasonably believed that he or she was being attacked or was immediately about to be attacked and that his or her personal safety was in immediate danger.
Factors that may be considered in determining whether a defendants apprehension of immediate harm was reasonable include
- relative size and strength of the persons involved,
- whether weapons were involved,
- the location of the incident,
- whether threats were made, and
- any other relevant factors arising from the circumstances of the event.
- The defendant must have done everything reasonably possible in the circumstances to avoid physical confrontation before resorting to force, including retreating or escaping. However, this does not mean that a person must expose himself or herself to additional danger in order to retreat.
Factors relevant to this issue are
- whether avenues of retreat or escape were available to him or her,
- how imminent the threat of harm was, and
- whether summoning aid would have helped.
- The law recognizes that a person who is attacked may have to decide how to respond quickly and under emotional strain. As Justice Holmes noted inBrown v. United States , 256 U.S. 335, 343 (1921), "[d]etached reflection cannot be demanded in the presence of an uplifted knife."
The requirement of retreat does not apply to one who is attacked in his or her own dwelling if the occupant reasonably believes that the intruder is about to kill or seriously injure the occupant. G.L. c. 278, § 8A. This rule only applies if the "victim" is in the home unlawfully. So if the "victim" was invited into the defendants home and only later began to attack the defendant, then the rule absolving the defendant from the necessity of attempting retreat would not apply. Commonwealth v. Painten , 429 Mass. 536, 545-46 (1999). The amount of force that can be used is that force which is necessary to protect the occupants. G.L. c. 278, § 8A.
- The defendant must have used no more force than reasonably necessary in the circumstances to defend himself or herself.
Factors relevant to the consideration of this issue include
- relative size and strength of the combatants,
- use of weapons,
- location of the incident,
- perception of the danger by the defendant, and
- availability of maneuvering room.
[h=2]Use of Deadly Force[/h]The use of deadly force in self-defense has additional requirements. Deadly force, which is "force intended or likely to cause death or great bodily harm," Commonwealth v. Klein, 372 Mass. 823, 827 (1977), may be used to repel an attack only under the following circumstances:
- where a person reasonably believes himself or herself to be in imminent danger of death or serious bodily harm;
- where the person uses all other proper means to avoid physical confrontation before resorting to deadly force (note: the provisions of G.L. c. 278, § 8A explained above apply to the use of deadly force in ones home or dwelling); and
- where the force used was no more than reasonably necessary under all circumstances.
The burden remains squarely on the Commonwealth to prove beyond a reasonable doubt that the defendant was not entitled to use deadly force or that the force was excessive. In murder cases, excessive use of deadly force in self-defense is manslaughter.Commonwealth v. Acevedo, 446 Mass. 435, 443 (2006); see also Commonwealth v. Glover, 76 Mass. App. Ct. 799, 804-09 (2010).
