Knock and Announce Rule

The knock and announce rule requires that police officers identify themselves, give notice of their purpose, and request entry before entering a dwelling. The rule has existed since the early common law and is considered part of the reasonableness requirement of the Fourth Amendment. The rule is intended to protect people in their home from unexpected and forcible entries and is based in part on the common law maxim that “a man's home is his castle.”

Exactly what constitutes identification and notice of purpose has been the subject of significant debate. Generally, what is required is that police officers (1) identify themselves as police officers, (2) request entry of the premises, (3) inform the occupants that they have the authority to enter (based either on possession of a search or arrest warrant, or on the existence of probable cause and an exigent circumstance), and (4) give the occupants an opportunity to admit them before they resort to forcible entry.

It is sufficient for police to identify themselves by merely stating “police.” The demand to enter can be as simple as “open the door;” it may also be inferred from statements such as “I have a search warrant.” Such statements carry the implicit notice that the officer has the lawful authority to enter the premises. The police must make the announcement in a manner in which the occupants can hear it—a whisper is not adequate.

Once notice and announcement are made, the police must give the occupants a reasonable opportunity to admit them before resorting to forcible entry. While refusal to admit the police is required before forcible entry is permitted, such refusal may be inferred from the circumstances, such as no response from the dwelling or the sound of people retreating from the door. The knock and announce rule is not intended to prevent police entry but merely to make such entries as peaceful and nondestructive as possible under the circumstances of the case.

Entry without notice is allowed in certain circumstances. These instances, often grouped together under the heading exigent circumstances, include, for example, danger to the officer seeking to enter the premises, the possibility of the destruction of evidence contained on the premises, and the possibility that the occupants will escape. Announcement is also unnecessary when it would be a “useless gesture,” meaning when the presence and purpose of the police is already known to the occupants. For an unannounced entry to withstand judicial scrutiny, the police officer must establish a reasonable belief that an exigent circumstance exists.

In Wilson v. Arkansas (1995), the Supreme Court held that the knock and announce rule was part of the Fourth Amendment requirement that searches be conducted in a reasonable manner. In Richards v. Wisconsin (1997), the Supreme Court held that the common law exceptions to the knock and announce rule were also part of the reasonableness requirement, thus largely importing the rule from the common law into the Fourth Amendment.

The knock and announce rule serves at least four purposes. First, the rule helps to prevent violence by reducing the number of unannounced entries into homes. Second, the rule helps reduce the destruction of property by providing the occupant with the opportunity to admit the police peacefully, eliminating the need for the police to break into the home. Third, the rule allows the homeowner to redirect police officers who are at the wrong address. Fourth, and perhaps most importantly, the rule helps to protect an individual's right to privacy.

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