What was the ruling in United States v. Leon?

The ruling in United States v. Leon established the "good faith" exception to the exclusionary rule. This landmark decision recognized that evidence obtained by law enforcement officers, despite a search warrant later found to be invalid, could still be admissible in court if the officers were acting under the belief that their warrant was valid and they were following established legal standards.

The rationale behind this ruling is that the exclusionary rule is intended to deter police misconduct, but if the officers relied on a warrant issued by a neutral magistrate, their conduct may not be considered reckless or intentional in violating someone's Fourth Amendment rights. Thus, as long as law enforcement acted with reasonable reliance on the warrant, the evidence obtained could be used in prosecutions, contributing to a more balanced approach between the rights of individuals and the needs of law enforcement to pursue justice.