In United States v. Brown, Docket No. 14-3754 (3d Cir. Feb. 22, 2017), the defendant raised Fifth and Sixth Amendment challenges to the use of dual juries (one for him and one for a co-defendant) at his trial. Although Brown's counsel raised no objection to the joint trial before dual juries, the Third Circuit reviewed the defendant's claim for plain error because there was no indication that the defendant "was actually aware of his due process and jury rights and that he himself - not just his counsel - knowingly sanctioned a procedure that arguably impinges on those rights."
Noting that the use of dual juries has very little precedent in the Third Circuit, the Court adopted the holdings of several other circuits in ruling that the use of dual juries is not per se unconstitutional. Instead, the practice will be upheld unless the defendant can show some specific, undue prejudice. While the Court stated that it was not encouraging the practice of using dual juries, due to the potentially significant complications inherent in such a practice, it nevertheless affirmed Brown's conviction because Brown had failed to show any prejudice in his case.