Is a defendant in a federal prosecution for murder on an Indian reservation entitled to an instruction on the lesser-included charge of manslaughter?

In Stevenson v. United States, supra, the issue was whether the defendant in a federal prosecution for murder on an Indian reservation was entitled to an instruction on the lesser-included offense of manslaughter. As here, the dispute was over the state of mind of the defendant at the time he committed an act which constituted the remaining elements of both the lesser and greater offenses. The court stated:

"The evidence as to manslaughter need not be uncontradicted or in any way conclusive upon the question; so long as there is some evidence upon the subject, the proper weight to be given it is for the jury to determine. . . . The evidence might appear to the court to be simply overwhelming to show that the killing was in fact murder, and not manslaughter . . . and yet, so long as there was some evidence relevant to the issue of manslaughter, the credibility and force of such evidence must be for the jury, and cannot be (a) matter of law for the decision of the court." Stevenson v. United States, supra, 162 U.S. at 314, 315, 16 S.Ct. at 839.

Moreover, the court reiterated the importance of the jury function when it continued: