In the 1983 case of Richardson v. United States, the Supreme Court ruled on whether a defendant's Sixth Amendment right to confront witnesses against them was violated when they were not allowed to cross-examine a psychiatric expert who had examined them but did not testify at trial. The court held that there was no violation because the psychiatrist's report was used only for sentencing and not for determining guilt or innocence. Therefore, it fell under an exception to the confrontation clause which allows such reports in sentencing hearings where reliability is ensured by other factors like professional ethics and standards. Furthermore, since defendants have no constitutional right to cross-examination at sentencing proceedings unless their sentence relies heavily on new factual findings about additional criminal conduct, Richardson’s rights were not infringed upon.

In the dissenting opinion for Richardson v. United States, Justice Stevens argued that the jury should have been allowed to consider whether or not Richardson had a reasonable belief that he was entitled to possess and distribute methaqualone tablets. He contended that this case involved an exception to the general rule of law because it dealt with a highly technical statute where even legal experts could disagree on its interpretation. Therefore, in such cases, defendants should be able to present evidence showing they believed their actions were lawful based on a reasonable understanding of the law. The majority's decision would deny defendants this right and potentially lead them into traps for unwary conduct. Furthermore, he disagreed with how lower courts interpreted "good faith" defense as requiring proof of reliance on professional advice which is too narrow and restrictive according to him.