Tennessee Pattern Instructions (T.P.I). Section 40.00. Defense
TN — CRIM. 40.07 DEFENSE OF THIRD PERSON
Included in the defendant’s plea of not guilty is [his] [her] plea of defense of a third person.
A person is justified in threatening or using force against another to protect a third person if:
(1) under the circumstances as the person reasonably believes them to be, the person would be justified, under the principles which apply to self-defense, in threatening or using force to protect against the use or attempted use of unlawful force reasonably believed to be threatening the third person sought to be protected;
(2) the person reasonably believes that the intervention is immediately necessary to protect the third person.
[The trial judge should now instruct the jury concerning the principles of self-defense, T.P.I. — CRIM. 40.06.]
If evidence is introduced supporting defense of a third person, the burden is on the state to prove beyond a reasonable doubt that the defendant did not act in defense of a third person.
If from all the facts and circumstances you find the defendant acted in defense of a third person, or if you have a reasonable doubt as to whether the defendant acted in defense of a third person, you must find [him] [her] not guilty.