In Dunn v. United States (1932) 284 U.S. 390, disapproved on another ground by United States v. Powell (1984) 469 U.S. 57, the court held that a person whom a jury finds guilty on one count cannot attack that conviction on the ground of inconsistency with the jury's not guilty verdict on another count. (Dunn, supra, at pp. 392-394.) " 'The most that can be said in such cases is that the verdict shows that either in the acquittal or the conviction the jury did not speak their real conclusions, but that does not show that they were not convinced of the defendant's guilt. We interpret the acquittal as no more than their assumption of a power which they had no right to exercise, but to which they were disposed through lenity.' " (Id. at p. 393.) "That the verdict may have been the result of compromise, or of a mistake on the part of the jury, is possible. But verdicts cannot be upset by speculation or inquiry into such matters." (Id. at p. 394.) In Powell, supra, 469 U.S. at pages 64-65, the high court lauded Dunn's "sound rationale" and observed that inconsistent verdicts "present a situation where 'error,' in the sense that the jury has not followed the court's instructions, most certainly has occurred, but it is unclear whose ox has been gored." As "imprudent and unworkable," Powell rejected the notion of allowing "criminal defendants to challenge inconsistent verdicts on the ground that in their case the verdict was not the product of lenity, but of some error that worked against them. Such an individualized assessment of the reason for the inconsistency would be based either on pure speculation, or would require inquiries into the jury's deliberations that courts generally will not undertake." (Id. at p. 66.) The high court noted "that a criminal defendant already is afforded protection against jury irrationality or error by the independent review of the sufficiency of the evidence undertaken by the trial and appellate courts." (Id. at p. 67.)