Interesting self-defense case
Richardson v. State, Mississippi Supreme Court, discussed over at the Volokh Conspiracy. Defendant was menaced by a guy who have moved in, became increasingly violent, and boasted of having been convicted of robbery and murder, of killing an informer in prison, and of belonging to a gang. Defendant eventually killed the guy, and the defense that he had come toward him, menacingly, with one hand behind his back.
The trial court refused to admit evidence that the decedent had in fact been convicted of robbery and murder, etc.. That'd be standard (if unjust, to my gut feeling). The American approach to self-defense keys on a reasonably fear of death or serious injury, and a person's fear could not have been based on what they did not then know (that the claims of conviction and past violence were in fact true).
But, the court reasons, the jury might have had questions about whether the decedent did in fact boast of those things. The fact that the boasts could be proven true might thus be some support for the proposition that the boasts were made. Ergo, the jury should have been allowed to hear of proof that the boasts were true.