In Franks v. Delaware, the U.S. Supreme Court ruled that a defendant has the right to challenge the veracity of a search warrant affidavit and request an evidentiary hearing (known as a "Franks Hearing") if they can make a substantial preliminary showing that false statements were knowingly or recklessly included in the affidavit by law enforcement, and if those false statements were necessary for finding probable cause. The case involved petitioner Larry Franks who was convicted of rape based on evidence obtained through such an allegedly flawed warrant. In its 7-2 decision, the court held that under Fourth Amendment protections against unreasonable searches and seizures, convictions cannot be based on evidence from warrants issued on deliberately or recklessly falsified affidavits.

In the dissenting opinion for Franks v. Delaware, Justice Blackmun argued that the majority's decision to allow defendants to challenge search warrants based on false statements made by police officers in their affidavits was a departure from established precedent. He expressed concern about the potential impact of this ruling on law enforcement, suggesting it could lead to an increase in litigation and hinder police work. Furthermore, he questioned whether such challenges would be effective at deterring perjury by law enforcement officials or improving accuracy in warrant applications. Instead, he suggested that other remedies like professional discipline or criminal prosecution might be more appropriate for addressing these issues.