I begin with the caveat that I am not able to give legal advice with respect to Missouri law.
The applicable statutes are MRS 563.031, 563.041 and 563.074. The castle doctrine is in section 031 and reads
(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.
- 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.
This allows deadly force in your “castle” and does not require retreat. If charged, this is an affirmative defense, meaning, you must formally plead the defense and then the state has to prove beyond a reasonable doubt that it was NOT self defense.
With respect to immunity, MRS 563.074 is relatively straight forward.
- Notwithstanding the provisions of section 563.016 , a person who uses force as described in sections 563.031 , 563.041 , 563.046 , 563.051 , 563.056 , and 563.061 is justified in using such force and such fact shall be an absolute defense to criminal prosecution or civil liability.
- The court shall award attorney’s fees, court costs, and all reasonable expenses incurred by the defendant in defense of any civil action brought by a plaintiff if the court finds that the defendant has an absolute defense as provided in subsection 1 of this section.
The question with respect to being able to bring a civil action is somewhat answered in the statute in section 2 where the defendant will be awarded fees and costs if the court finds it was an absolute defense. This leads me to believe that it will become a question of law to be determined by the judge instead of a jury.
I hope this helps.