In the United States v. Gagnon et al., 1984, the U.S Supreme Court ruled that defendants do not have a constitutional right to be present during in-chambers discussions between judge and juror about potential jury bias. The case involved four co-defendants who were convicted of various federal crimes related to drug trafficking. During their trial, one of the jurors asked to speak privately with the judge due to feeling threatened by one defendant's gaze. This conversation took place without any of the defendants or their counsel present which led them appealing on grounds that they had been denied rights under Federal Rule Criminal Procedure 43(a) and Sixth Amendment Confrontation Clause - both guaranteeing a defendant’s presence at every stage of trial unless unruly behavior warrants exclusion. However, Supreme Court held that these rights are not absolute and can be outweighed by other interests such as protecting juror’s ability to deliberate freely without fear or intimidation.

In the dissenting opinion for United States v. Gagnon et al., Justice Brennan, joined by Justice Marshall, disagreed with the majority's view that a defendant must assert his right to be present at all stages of trial in order to claim violation of this right. They argued that it is not reasonable to expect defendants to know and understand every aspect of their rights without being informed by the court or counsel. The dissent pointed out that many defendants are unfamiliar with legal proceedings and may not even realize they have been excluded from an important part of their trial until after it has occurred. Therefore, they contended that courts should automatically inform defendants about their right to be present during any stage where evidence against them might be presented or discussed - rather than placing the burden on defendants themselves.