Which U.S. Supreme Court case established the “good faith” rule for search warrants?

The U.S. Supreme Court case that established the "good faith" rule for search warrants is United States v. Leon. This case introduced the principle that evidence obtained in violation of a person's Fourth Amendment rights could still be admissible in court if law enforcement officers were acting on what they reasonably believed to be a valid search warrant. The "good faith" exception allows for the use of evidence when officers unintentionally make a mistake regarding the validity of a warrant, thereby encouraging proper law enforcement procedures without unduly harming the prosecution of criminal cases.

The ruling in United States v. Leon acknowledges that law enforcement personnel should not be penalized for technical errors made in good faith, as long as those errors do not involve reckless disregard for constitutional rights. This decision helps maintain a balance between the need for effective law enforcement and the protection of individual rights under the Constitution.