In US v. Marcus, No. 08-1341, perhaps more popularly known as the "S&M Svengali" case, the Supreme Court reversed the Second Circuit's reversal of defendant's forced labor and sex trafficking conviction, on the ground that the Second Circuit's plain error standard, under which a retrial was necessary whenever there was any possibility, no matter how unlikely, that the jury could have convicted based exclusively on defendant's conduct prior to the enactment of the statute under which he was charged, was inconsistent with the Supreme Court's approach to plain error, under which: 1) the error must affect the appellant's substantial rights, which in the ordinary case means it affected the outcome of the district court proceedings; and 2) the error must seriously affect the fairness, integrity or public reputation of judicial proceedings.
As the Court wrote: "The question before us concerns an appellate court's "plain error" review of a claim not raised at trial. See Fed. Rule Crim. Proc. 52(b). The Second Circuit has said that it must recognize a "plain error" if there is "any possibility," however remote, that a jury convicted a defendant exclusively on the basis of actions taken before enactment of the statute that made those actions criminal. 538 F.3d 97, 102 (2008) (per curiam) (emphasis added). In our view, the Second Circuit's standard is inconsistent with this Court's "plain error" cases. We therefore reverse."