547 U.S. 586 (2006)
Hudson v. Michigan is a landmark decision in Fourth Amendment jurisprudence that significantly narrows the application of the exclusionary rule.
Does a violation of the Fourth Amendment's knock-and-announce requirement, when officers execute a valid search warrant, require suppression of the evidence found in the ensuing search?
The exclusionary rule does not apply to violations of the knock-and-announce requirement when officers execute a valid search warrant. Although knock-and-announce is part of the Fourth Amendment's reasonableness inquiry, the interests it protects (life, limb, property, and privacy/dignity) are not designed to shield evidence described in a warrant from seizure. Because the causal link between a knock-and-announce violation and the discovery of evidence under a valid warrant is attenuated, and because the social costs of exclusion are substantial while alternative deterrents (civil liability and internal discipline) exist, suppression is not an appropriate remedy for such violations.
No. Evidence discovered pursuant to a valid search warrant is not subject to suppression solely because officers violated the knock-and-announce requirement before entering.
Hudson is a cornerstone in the modern, remedial law of the Fourth Amendment, marking a clear limit on the exclusionary rule. It teaches that not every constitutional violation triggers suppression; courts must ask what interest the violated rule protects and whether excluding evidence would meaningfully vindicate that interest in light of the rule's costs. For law students, Hudson is essential for analyzing remedy questions: identify (1) the underlying constitutional right, (2) the distinct purpose of that right, (3) the causal connection between the violation and the evidence, and (4) the availability and adequacy of alternative deterrents. Practically, Hudson aligns with a broader trend narrowing suppression (see, e.g., Herring v. United States and Davis v. United States) and highlights federalism space for states to provide greater remedies under state law. It also underscores that knock-and-announce remains a constitutional requirement—Wilson and Richards are not overruled—but that its breach typically yields civil or administrative, not evidentiary, consequences.