Justification and excuse are different defenses in a United States criminal case.
[1]: 513 Both defenses admit that the defendant committed an act proscribed by law.
[1]: 513–4 Martin v. Ohio (1986) established that states may make justification an affirmative defense, placing the burden of proof on defendant.
[1]: 18 Patterson v. New York (1977) established that states may make excuses, such as involving mental state, an affirmative defense, rather than part of the mens rea element the prosecution must prove beyond a reasonable doubt.
What is justified under a utilitarian perspective might be excused under a retributivist standpoint, and vice versa.