Also known as: knock and announce standards · knock-and-announce rule · knock and announce rule · knock-and-announce requirement · Wilson rule
Written by attorneys · grounded in primary & secondary sources — see below
A Fourth Amendment principle requiring law enforcement officers to knock and announce their presence before forcibly entering a dwelling to execute a search warrant. The requirement protects interests in life, property, privacy, and dignity during entry. A violation does not trigger the exclusionary rule when officers otherwise hold a valid warrant.
Narcotics officers obtained a warrant for Dana's apartment. Believing drugs might be flushed, they forced the door without knocking or announcing. They seized pill bottles and logs inside. Dana's motion to suppress the evidence fails because the knock-and-announce violation does not require exclusion of items seized under a valid warrant.
Officers responded to a home where a juvenile was striking an adult. They entered through the back door without knocking after seeing the ongoing violence. The entry satisfied knock-and-announce standards because exigent circumstances made announcement unreasonable. Evidence obtained inside remains admissible.
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Officers arrested a driver for suspected drunk driving. They sought a warrantless blood draw to prevent dissipation of alcohol. The driver argued that the delay for a warrant would destroy evidence. The court holds that the natural metabolization of alcohol alone does not create a per se exigency justifying a warrantless search.
Officers knocked on an apartment door after smelling marijuana. When they heard movement inside, they announced their presence and forced entry. The occupant claims officers manufactured the exigency by knocking. The court rules that the knock itself did not create the exigency that justified the warrantless entry.
No. The exclusionary rule does not apply to knock-and-announce violations during execution of a valid search warrant. The interests protected by the rule are too attenuated from the later evidentiary use of seized items, and alternative remedies such as civil suits and internal discipline suffice.
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It protects life and safety of occupants and officers, prevents unnecessary property damage, and preserves privacy and dignity by giving occupants a chance to answer the door peacefully.
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Officers may enter without knocking when exigent circumstances exist, such as imminent risk of evidence destruction, danger to officers, or escape of a suspect. The determination is based on the totality of circumstances at the time of entry.
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…rule. The Michigan Supreme Court also affirmed. Held: The exclusionary rule does not apply to violations of the knock-and-announce requirement. Majority opinion Opinion of Justice Scalia The common-law principle that law enforcement officers must announce their presence before entering a dwelling has long been part of…