Mo. Rev. Stat. § 563.074: Justification as an absolute defense, when.

1. 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.

2. 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.