In Sullivan v. Louisiana, 508 U.S. 275 (1993), the United States Supreme Court explained that "the Fifth Amendment requirement of proof beyond a reasonable doubt and the Sixth Amendment requirement of a jury verdict are interrelated" (Sullivan, supra, 508 U.S. at p. 278), and thus "the jury verdict required by the Sixth Amendment is a jury verdict of guilty beyond a reasonable doubt." (Ibid.) In Sullivan, the high federal court held that a constitutionally deficient reasonable doubt instruction deprives the accused of his or her federal constitutional right to a jury verdict of guilty beyond a reasonable doubt and is a reversible-per-se "structural error" that is not amenable to harmless error analysis and will always invalidate a conviction. (Sullivan, supra, 508 U.S. at pp. 277-278.) In Sullivan, the Supreme Court concluded that, "in his instructions to the jury, the trial judge gave a definition of 'reasonable doubt' that was . . . essentially identical to the one held unconstitutional in Cage v. Louisiana (1990) 498 U.S. 39." (Sullivan, supra, 508 U.S. at p. 277.) The high federal court referred to the Sullivan instruction as a "constitutionally deficient reasonable-doubt instruction." (Id. at p. 276.) The Sullivan court explained that, "there being no jury verdict of guilty-beyond-a-reasonable-doubt, the question whether the same verdict of guilty-beyond-a-reasonable-doubt would have been rendered absent the constitutional error is utterly meaningless." (Id. at p. 280.) The parties agreed the trial court had provided an erroneous reasonable-doubt instruction to the jury. Id. at 277. The issue, then, was whether such error was structural or subject to harmless-error review. Id. at 278-79. The Supreme Court concluded a harmless-error analysis in that case would be "illogical." Id. at 280. It explained that, under harmless-error review, the court would need to consider "whether the guilty verdict actually rendered in this trial was surely unattributable to the erroneous instruction." Id. at 279. But, because the erroneous reasonable-doubt instruction rendered the verdict defective as a whole, there was "no jury verdict within the meaning of the Sixth Amendment" to consider under harmless-error review. Id. at 280. The trial court gave the jury a definition of "reasonable doubt" which was unconstitutional. ( Sullivan v. Louisiana, supra, 508 U.S. at p. 277.) The Supreme Court noted that "although most constitutional errors have been held amenable to harmless-error analysis . . .,some will always invalidate the conviction." ( Id. at p. 279.) Harmless error analysis requires a determination "whether the guilty verdict actually rendered . . . was surely unattributable to the error." (Ibid.) Where "there has been no jury verdict within the meaning of the Sixth Amendment" right to trial by jury, harmless error analysis cannot be applied. ( Id. at p. 280.) Absent "the Fifth Amendment requirement of proof beyond a reasonable doubt," there can be no jury verdict consistent with the Sixth Amendment right to trial by jury. ( Id. at p. 278.) If, the court concluded, "the instructional error consists of a misdescription of the burden of proof, this vitiates all the jury's findings," and there can be no verdict of guilt beyond a reasonable doubt. ( Id. at p. 281.) The United States Supreme Court held that a constitutionally deficient reasonable doubt instruction was structural error. Id. at 281-82. After noting that most constitutional errors are amenable to harmless error analysis, the Court reasoned that when an improper burden of proof has been applied, the framework for harmless error analysis does not exist. Id. at 279-80. The Court explained that, in applying harmless error review, the question that reviewing courts are called upon to consider is not what effect the error had on the jury, but what effects it had on the guilty verdict itself. Id. at 279. The inquiry, in other words, is not whether, in a trial that occurred without the error, a guilty verdict would surely have been rendered, but whether the guilty verdict actually rendered in this trial was surely unattributable to the error. That must be so, because to hypothesize a guilty verdict that was never in fact rendered -- no matter how inescapable the findings to support that verdict might be -- would violate the jury-trial guarantee. Id. Where no jury verdict of guilt beyond a reasonable doubt has been rendered, there has been no jury verdict within the meaning of the Sixth Amendment, so "the question whether the same verdict of guilty-beyond-a-reasonable-doubt would have been rendered absent the constitutional error is utterly meaningless." Id. at 280. In Sullivan v. Louisiana, a defective "reasonable doubt" instruction violated the defendant's Fifth and Sixth Amendment rights to have the charged offense proved beyond a reasonable doubt. 508 U.S. at 280. The Supreme Court concluded that such error was not subject to harmless-error analysis because it "vitiates all the jury's findings," id. at 281, and produces "consequences that are necessarily unquantifiable and indeterminate," id. at 282. In Sullivan, the Supreme Court held that where a jury applies an incorrect reasonable doubt instruction, the verdict is unreliable because it lacks one of the basic protections of our criminal justice system, and the consequences of the error are "necessarily unquantifiable and indeterminate." Sullivan, 508 U.S. at 282. The Court also noted that error in the trial mechanism is not subject to the type of quantitative analysis that is required in a review for harmless error. Id. at 281-82. Thus, the Court concluded that denial of the right to a jury verdict beyond a reasonable doubt had consequences that were "necessarily unquantifiable and indeterminate" and therefore "unquestionably qualified as 'structural error.'" Id.