In Sandstrom v. Montana, 442 U.S. 510 (1979), the defendant was charged under Montana law with "deliberate homicide," which requires that the defendant "purposely or knowingly cause the death" of the victim. 442 U.S. at 512. At the close of the evidence, the prosecution requested that the trial judge instruct the jury that "the law presumes that a person intends the ordinary consequences of his voluntary acts." Id. at 513. Defense counsel objected stating that "'the instruction had the effect of shifting the burden of proof on the issue of' purpose or knowledge" on to the defendant. Id. Overruling defense counsel's objection, the court instructed the jury in accordance with the prosecutor's request. Id. After the jury returned a guilty verdict, the defendant raised this issue on appeal. Affirming the judgment of the trial court, the Supreme Court of Montana declined to find a constitutional violation in this instruction. Id. But the United States Supreme Court did. Holding that the instruction violated the defendant's due process rights, the Court declared that the "jury may have interpreted the judge's instruction as constituting either a burden-shifting presumption . . . or a conclusive presumption . . . ." Id. at 524. The Supreme Court explained that jury instructions are unconstitutional when a reasonable juror might understand them to create either an irrebuttable presumption, or to create a mandatory but rebuttable presumption that shifts the burden of persuasion on any element of the offense to the defendant. Sandstrom confessed to killing a young woman, but argued that his personality disorder, aggravated by alcohol consumption, prevented him from doing so "purposely or knowingly." Id., 442 U.S. at 512. The trial court instructed the jury that a competent person's acts are presumed to be the product of the person's will, and that such persons are presumed to intend the consequences of their acts. The Supreme Court reversed Sandstrom's murder conviction because the jury might have misunderstood and misapplied that instruction. See id., 442 U.S. at 524. The Court reasoned that, as given, the instruction might have led jurors to incorrectly conclude that once the prosecution showed that the defendant was "of sound mind and discretion," the defense bore the burden of disproving the evidentiary presumption that he intended to kill the victim. See id., 442 U.S. at 517-24. Whether the instructions were viewed as creating an unrebuttable presumption, or as creating such a rebuttable, burden of proof-shifting presumption, Sandstrom had been deprived of his right to due process of law. See id.