In Henderson et al. v. United States (1985), the U.S Supreme Court ruled on a case involving the interpretation of Federal Rule of Criminal Procedure 52(b). The petitioners, who were convicted for mail fraud, argued that their convictions should be reversed because they were not informed about an essential element of the offense during their trial - namely, that to commit mail fraud one must have intended to defraud someone out of money or property. However, this information was omitted from jury instructions and no objection was made at trial by defense counsel. The Supreme Court held that even though there had been a "plain error" in omitting this instruction from the jury charge, it did not affect substantial rights as required by Rule 52(b) for reversal since evidence against them was overwhelming and hence any rational juror would have found them guilty beyond reasonable doubt with correct instructions too.

In the dissenting opinion for Henderson et al. v. United States, Justice Brennan argued that the majority's decision to uphold a conviction based on evidence obtained through an unlawful search was fundamentally flawed. He contended that this ruling undermined Fourth Amendment protections against unreasonable searches and seizures by allowing illegally obtained evidence to be used in court if it could have been discovered through legal means. This "inevitable discovery" doctrine, he believed, would encourage law enforcement officers to bypass constitutional safeguards with impunity as long as they could later justify their actions under this rule. Furthermore, he criticized the majority for applying this new doctrine retroactively without any clear guidelines or limitations in place - a move which he saw as both unfair and potentially dangerous due its potential misuse by police forces across the country.