(1) Except as provided in (2), a private person acting on their own account is justified in using physical force on someone else when & to the extent that they reasonably believe it necessary to make an arrest or to prevent the escape from custody of an arrested person whom they have arrested under 133.225 (arrest by private person)

(2) a private person acting under the circumstances prescribed in (1) is justified in using deadly physical force only when they reasonably believe it necessary for self-defense or to defend a third person from what they reasonably believes to be the use or imminent use of deadly physical force