Whether an acknowledged instructional error requires reversal where a reviewing court cannot determine if the jury based its verdict on the legally erroneous instruction or an alternative, valid theory of liability

QUESTION PRESENTED Charles Johnson was convicted of two counts of possessing a firearm during a crime of violence. 18 U.S.C. § 924(c). The district court instructed the jury that either of two underlying crimes could serve as a predicate crime of violence for the firearm convictions: (1) Hobbs Act robbery, and (2) conspiracy to commit Hobbs Act robbery. Based on that instruction, the jury returned a guilty verdict on a general verdict form that did not require it to choose between these two predicate offenses. On appeal, the Fourth Circuit conceded that, because conspiracy to commit Hobbs Act robbery is not a crime of violence, it was plain error to instruct the jury otherwise. But it held that the error did not impact Mr. Johnson’s substantial rights because Hobbs Act robbery is a crime of violence under the statute and the district court correctly instructed the jury on this alternative theory of liability. The question presented is whether an acknowledged instructional error requires reversal where a reviewing court cannot determine if the jury based its verdict on the legally erroneous instruction or an alternative, valid theory of liability. i