13-406. Justification; defense of a third
person


A person is justified in threatening or using physical force or deadly physical
force against another to protect a third person if:


1. Under the circumstances as a reasonable person would believe them to be, such
person would be justified under section 13-404 or 13-405 in threatening or using physical
force or deadly physical force to protect himself against the unlawful physical force or
deadly physical force a reasonable person would believe is threatening the third person
he seeks to protect; and


2. A reasonable person would believe that such person's intervention is immediately
necessary to protect the third person.