Herring V. United States - Background - The Evolution of The Exclusionary Rule

The Evolution of The Exclusionary Rule

"The Fourth Amendment contains no provision expressly precluding the use of evidence obtained in violation of its commands," but in Weeks v. United States (1914) and Mapp v. Ohio (1961), the Supreme Court created the exclusionary rule, which generally operates to suppress - i.e. prevent the introduction at trial of - evidence obtained in violation of Constitutional rights. "Suppression of evidence, however, has always been last resort, not first impulse. The exclusionary rule generates substantial social costs, which sometimes include setting the guilty free and the dangerous at large." In United States v. Leon, the Supreme Court clarified that the exclusionary rule "operates as a judicially created remedy designed to safeguard Fourth Amendment rights generally through its deterrent effect, rather than a personal constitutional right of the party aggrieved." Application of the rule should be sensitive to this purpose, the court said: If suppression "does not result in appreciable deterrence," the court had said, "its use ... is unwarranted."

Thus, for example, in Leon itself, the court concluded that the fruits of a search based on a search warrant later found defective should not be excluded because the rule's deterrent purpose "will only rarely be served by applying it in such circumstances," and in Arizona v. Evans, the court concluded that the fruits of a search based on an arrest warrant that was no longer valid, but that was still listed in the police system because of an error by the issuing court's clerk, should not be excluded because such exclusion would have no deterrent effect.