How do we review for abuse of abuse of power when a juror is dismissed after deliberations have begun?

We review for abuse of discretion both the dismissal of a juror after deliberations have commenced and the denial of a motion for a new trial based on such a dismissal. United States v. Vartanian , 476 F.3d 1095, 1098 (9th Cir. 2007) ; United States v. King , 660 F.3d 1071, 1076 (9th Cir. 2011). The district court's factual findings relating to the issue of juror misconduct are reviewed for clear error. Vartanian , 476 F.3d at 1098. The decision to excuse a juror is committed to the district court's discretion and we must affirm unless we are left with the definite and firm conviction that the court committed a clear error of judgment in reaching its conclusion after weighing the relevant factors. United States v. Beard , 161 F.3d 1190, 1194 (9th Cir. 1998) (quoting United States v. Egbuniwe , 969 F.2d 757, 761 (9th Cir. 1992) (internal quotation marks omitted)).