1.  A private person who has been directed by a person he or she reasonably believes to be a law enforcement officer to assist such officer to effect an arrest or to prevent escape from custody may, subject to the limitations of subsection 3 of this section, use physical force when and to the extent that he or she reasonably believes such to be necessary to carry out such officer’s direction unless he or she knows or believes that the arrest or prospective arrest is not or was not authorized.

 2.  A private person acting on his or her own account may, subject to the limitations of subsection 3 of this section, use physical force to arrest or prevent the escape of a person whom such private person reasonably believes has committed an offense, and who in fact has committed such offense, when the private person’s actions are immediately necessary to arrest the offender or prevent his or her escape from custody.

Terms Used In Missouri Laws 563.051

  • Arrest: Taking physical custody of a person by lawful authority.
  • 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.
  • Felony: A crime carrying a penalty of more than a year in prison.
  • person: may extend and be applied to bodies politic and corporate, and to partnerships and other unincorporated associations. See Missouri Laws 1.020
  • Private person: any person other than a law enforcement officer. See Missouri Laws 563.011

 3.  A private person in effecting an arrest or in preventing escape from custody is justified in using deadly force only:

 (1)  When deadly force is authorized under other sections of this chapter; or

 (2)  When he or she reasonably believes deadly force is authorized under the circumstances and he or she is directed or authorized by a law enforcement officer to use deadly force; or

 (3)  When he or she reasonably believes such use of deadly force is immediately necessary to arrest a person who at that time and in his or her presence:

 (a)  Committed or attempted to commit a class A felony or murder; or

 (b)  Is attempting to escape by use of a deadly weapon.

 4.  The defendant shall have the burden of injecting the issue of justification under this section.