Whether charges are properly joined in an indictment is a question of law that we review de novo. See United States v. Cardwell, 433 F.3d 378, 384-85 (4th Cir.2005). 'If the initial joinder was not proper, however, we review this nonconstitutional error for harmlessness, and reverse unless the misjoinder resulted in no `actual prejudice' to the defendant[ ] `because it had [no] substantial and injurious effect or influence in determining the jury's verdict.'' United States v. Mackins, 315 F.3d 399, 412 (4th Cir.2003) (quoting United States v. Lane, 474 U.S. 438, 449, 106 S.Ct. 725, 88 L.Ed.2d 814 (1986)). If misjoinder is found, the Government bears the burden of demonstrating that any error resulting from the misjoinder was harmless. Mackins, 315 F.3d at 412.
An error involving misjoinder '`affects substantial rights' and requires reversal only if the misjoinder results in actual prejudice because it `had substantial and injurious effect or influence in determining the jury's verdict.'' United States v. Lane, 474 U.S. 438, 449, 106 S.Ct. 725, 88 L.Ed.2d 814 (1986) (quoting Kotteakos v. United States, 328 U.S. 750, 776, 66 S.Ct. 1239, 90 L.Ed. 1557 (1946)) (emphasis added); see also Mackins, ...