In Desist et al. v. United States (1968), the U.S Supreme Court ruled on whether evidence obtained through electronic surveillance, prior to the court's decision in Katz v. United States, could be used in a trial if it would have been deemed unconstitutional under Katz standards. The defendants were convicted of conspiring to distribute and sell heroin based on evidence gathered from wiretaps authorized by federal law enforcement officials without judicial approval before Katz was decided upon. They argued that this violated their Fourth Amendment rights against unreasonable searches and seizures as defined by the new standard set in Katz. The Supreme Court held that its ruling in Katz should not apply retroactively; therefore, pre-Katz surveillance did not violate the Fourth Amendment because it complied with then-existing legal norms at the time of recording - even though such actions would be considered unconstitutional post-Katz due to changes made regarding privacy expectations and protections against warrantless wiretapping.

In the dissenting opinion for Desist et al. v. United States, Justice Harlan argued that the majority's decision to apply a new constitutional rule retroactively was inappropriate and inconsistent with previous rulings of the court. He contended that such an approach could undermine public trust in law enforcement by suggesting that police conduct previously deemed lawful might suddenly be considered unconstitutional due to changes in legal interpretation. Furthermore, he believed it would place undue burdens on courts by potentially reopening countless cases where evidence had been obtained under rules now seen as outdated or incorrect. Instead, Justice Harlan proposed a more balanced approach: new constitutional interpretations should only apply prospectively from the date of judgment unless they put "certain kinds of primary, private individual conduct beyond the power of criminal law-making authority to proscribe" or if they require observance of procedures without which "the likelihood of an accurate conviction is seriously diminished."