In the case of Carman L. Deck v. Missouri, 2004, the U.S. Supreme Court ruled that it was unconstitutional to shackle a defendant in front of a jury during the penalty phase of a capital trial unless there is an exceptional need for such restraints. The court held that visible shackling undermines the presumption of innocence and infringes on a defendant's right to counsel by interfering with his or her ability to communicate effectively with their attorney during trial proceedings. Carman Deck had been convicted twice for murder and sentenced to death both times; however, his first conviction was overturned due to ineffective assistance from his lawyer at sentencing stage. During his second sentencing hearing, he was visibly restrained which led him appealing again arguing this prejudiced jurors against him. The Supreme Court agreed stating that while courts have discretion over physical restraints in courtroom settings based on security concerns or risk factors associated with specific defendants; they must provide justifiable reasons before doing so especially when it could potentially prejudice juries' perceptions about defendants' guilt or dangerousness thereby affecting outcomes unfairly.

In the dissenting opinion for Carman L. Deck v. Missouri, Justice Clarence Thomas, joined by Justice Antonin Scalia, argued that there is no historical or contemporary consensus against shackling a defendant during the penalty phase of a capital trial to support it being considered as inherently prejudicial. They contended that the majority's decision was not based on any established legal principle but rather on their own subjective feelings and beliefs about what constitutes fairness and decency. The dissenters pointed out that many courts have allowed visible restraints during sentencing proceedings without causing fundamental unfairness or undermining public confidence in justice system. They further noted that some jurisdictions even require defendants to be restrained at all times in courtrooms regardless of whether they pose security risks or not.