1.  A person may, subject to the provisions of subsection 2 of this section, use physical force upon another person when and to the extent he or she reasonably believes such force to be necessary to defend himself or herself or a third person from what he or she reasonably believes to be the use or imminent use of unlawful force by such other person, unless:

 (1)  The actor was the initial aggressor; except that in such case his or her use of force is nevertheless justifiable provided:

Terms Used In Missouri Laws 563.031

  • Deadly force: physical force which the actor uses with the purpose of causing or which he or she knows to create a substantial risk of causing death or serious physical injury. See Missouri Laws 563.011
  • Defendant: In a civil suit, the person complained against; in a criminal case, the person accused of the crime.
  • Dwelling: any building, inhabitable structure, or conveyance of any kind, whether the building, inhabitable structure, or conveyance is temporary or permanent, mobile or immobile, which has a roof over it, including a tent, and is designed to be occupied by people lodging therein at night. See Missouri Laws 563.011
  • Felony: A crime carrying a penalty of more than a year in prison.
  • Forcible felony: any felony involving the use or threat of physical force or violence against any individual, including but not limited to murder, robbery, burglary, arson, kidnapping, assault, and any forcible sexual offense. See Missouri Laws 563.011
  • person: may extend and be applied to bodies politic and corporate, and to partnerships and other unincorporated associations. See Missouri Laws 1.020
  • Private property: any real property in this state that is privately owned or leased. See Missouri Laws 563.011
  • Property: includes real and personal property. See Missouri Laws 1.020
  • Residence: a dwelling in which a person resides either temporarily or permanently or is visiting as an invited guest. See Missouri Laws 563.011
  • State: when applied to any of the United States, includes the District of Columbia and the territories, and the words "United States" includes such district and territories. See Missouri Laws 1.020
  • Unlawfully enter: a person unlawfully enters in or upon premises or private property when he or she enters such premises or private property and is not licensed or privileged to do so. See Missouri Laws 563.011

 (a)  He or she has withdrawn from the encounter and effectively communicated such withdrawal to such other person but the latter persists in continuing the incident by the use or threatened use of unlawful force; or

 (b)  He or she is a law enforcement officer and as such is an aggressor pursuant to section 563.046; or

 (c)  The aggressor is justified under some other provision of this chapter or other provision of law;

 (2)  Under the circumstances as the actor reasonably believes them to be, the person whom he or she seeks to protect would not be justified in using such protective force;

 (3)  The actor was attempting to commit, committing, or escaping after the commission of a forcible felony.

 2.  A person shall not use deadly force upon another person under the circumstances specified in subsection 1 of this section unless:

 (1)  He or she reasonably believes that such deadly force is necessary to protect himself, or herself or her unborn child, or another against death, serious physical injury, or any forcible felony;

 (2)  Such force is used against a person who unlawfully enters, remains after unlawfully entering, or attempts to unlawfully enter a dwelling, residence, or vehicle lawfully occupied by such person; or

 (3)  Such force is used against a person who unlawfully enters, remains after unlawfully entering, or attempts to unlawfully enter private property that is owned or leased by an individual, or is occupied by an individual who has been given specific authority by the property owner to occupy the property, claiming a justification of using protective force under this section.

 3.  A person does not have a duty to retreat:

 (1)  From a dwelling, residence, or vehicle where the person is not unlawfully entering or unlawfully remaining;

 (2)  From private property that is owned or leased by such individual; or

 (3)  If the person is in any other location such person has the right to be.

 4.  The justification afforded by this section extends to the use of physical restraint as protective force provided that the actor takes all reasonable measures to terminate the restraint as soon as it is reasonable to do so.

 5.  The defendant shall have the burden of injecting the issue of justification under this section.  If a defendant asserts that his or her use of force is described under subdivision (2) of subsection 2 of this section, the burden shall then be on the state to prove beyond a reasonable doubt that the defendant did not reasonably believe that the use of such force was necessary to defend against what he or she reasonably believed was the use or imminent use of unlawful force.