Wilson v. Arkansas

The Supreme Court held that the common law knock and announce principle forms a part of the Fourth Amendment reasonableness test. An officer’s unannounced entry into a home can be, in some circumstances, unreasonable under the Fourth Amendment. In evaluating the scope of the reasonableness requirement, the Court considers the traditional protections against unreasonable searches and seizures afforded by the common law at the time of the framing. Given the longstanding common law endorsement of the practice of announcement, and the great number of commentaries, constitutional provisions, statutes, and cases supporting the knock and announce principle, the Court held that whether officers announced their presence and authority before entering a dwelling should be among the factors to be considered in assessing a search’s reasonableness.

NOTE: The burden that may result from an entry in violation of 18 U.S.C. § 3109 is limited to a civil liability claim and not the loss of evidence through the exclusionary rule. See Hudson v. Michigan.