In the case of Wainwright v. Greenfield, 1985, the U.S. Supreme Court ruled in favor of respondent Robert Allen Greenfield. The court held that a defendant's silence during post-Miranda warnings could not be used as evidence of his sanity at trial. Greenfield was arrested and read his Miranda rights but remained silent after being questioned about an alleged sexual battery incident; this silence was later presented by prosecutors as proof of his mental competency to stand trial for the crime he had been accused of committing. However, Justice Thurgood Marshall delivered the opinion stating that using a defendant’s post-arrest, post-Miranda warning silence against him violated due process because it penalized him for exercising his constitutional right to remain silent following arrest and receipt of Miranda warnings.

In the dissenting opinion for Wainwright v. Greenfield, Justice Brennan, joined by Justices Marshall and Blackmun, argued that the majority's decision undermined a defendant's Fifth Amendment rights. They contended that silence during post-Miranda questioning should not be used as evidence of sanity at trial because it violates the right against self-incrimination. The dissent emphasized that Miranda warnings are designed to inform suspects of their rights - including the right to remain silent - and using this silence against them contradicts these protections. Furthermore, they expressed concern about chilling effects on defendants' willingness to exercise their rights if such silence could be used against them in court.