Whether when applying plain-error review based upon an intervening United States Supreme Court decision, a circuit court of appeals may review matters outside the trial record to determine whether the error affected a defendant's substantial rights or impacted the fairness, integrity, or public reputation of the trial?

QUESTION PRESENTED FOR REVIEW In Rehaif v. United States, 139 S.Ct. 2191 (2019), this Court held that, in a prosecution under 18 U.S.C. §§ 922(g) and 924(a)(2), the government must prove not only that the defendant knew he possessed a firearm, but also that he knew he belonged to the relevant category of persons prohibited from firearm possession. This term, the Court granted certiorari in Greer v. United States, No. 19-8709, which presents the same question as for Mr. Brooks-Davis: Whether when applying plain-error review based upon an intervening United States Supreme Court decision, a circuit court of appeals may review matters outside the trial record to determine whether the error affected a defendant’s substantial rights or impacted the fairness, integrity, or public reputation of the trial? i