What is the knock and announce rule?

The knock and announce rule is a legal rule mandating that police cannot just break down someone's door in order to execute a search warrant. Under the knock and announce rule, police need to knock on the door, announce their authority to search the premises and wait a reasonable period of time before they enter. Only if a person fails to allow a search after the police identify themselves can the police forcibly come in. 

Understanding the Knock and Announce Rule

Both the federal government and individual states have put the knock and announce rule into law. For example, the United States Code says that a police officer can break windows or doors to execute a search warrant only if he has first announced himself, made his authority to search clear, announced his purpose and made his intent to search clear.

Most states use similar wording to the federal government in their own knock and announce rules. In Washington State, for example, the law says that police officers can break inner doors, outer doors or windows of a dwelling only if they provide notice of their right to be there and are still denied entry.  

The Purpose of the Knock and Announce Rule

The knock and announce rule protects a person's right to be free from an unreasonable search or seizure. Not only does the Fourth Amendment of the U.S. Constitution protect people from being subjected to warrantless searches, but it also gives people the right to have searches conducted in a reasonable and fair manner.

Courts have read the Fourth Amendment, therefore, to protect a person from having police simply storm his home without first giving him a chance to let them in by knocking and announcing their presence. In fact, in one Supreme Court case called Ker v. California, the court held that the Fourth Amendment "undoubtedly" included the right to have a police officer knock first. 

Knock and Announce Rule Exceptions

Although the knock and announce rule exists to protect a Constitutional right to reasonable searches, the rule also has to be weighed against the interest of justice. This means that the rule won't apply in every single case. In a sense, the rule establishes a presumption that the police should knock, but that presumption can be rebutted if there are other persuasive reasons why the police did not knock and announce.

In a case called Richards v. Wisconsin (520 U.S. 385) the court outlined what some of the exceptions to the knock and announce rule are. For instance, police don't have to knock if doing so would create an unreasonable risk to their safety or to the safety of the building occupants. Police also don't have to knock if doing so would give the suspects inside the chance to destroy evidence. In drug cases, for example, if police believe that the building occupants will just flush the drugs down the toilet when the police come knocking at the door, then they may be able to enter unannounced.

Richards also made clear, however, that there are no blanket exceptions to the knock and announce rule. In other words, just because police are searching for drugs doesn't automatically mean they can just come in. Each situation where the police enter without knocking has to be evaluated in light of the circumstances and context of that particular case to determine if law enforcement acted reasonably or not.

Law enforcement may also obtain something called a "no-knock" warrant if they know in advance that they need to enter without altering the occupants. The police will have to prove the need for this type of warrant when they obtain it, but if they convince a judge it is necessary, then there will be no basis for arguing that law enforcement acted improperly as a result of entering without knocking.

What if the Police Violate the Knock and Announce Rule?

If the police violate the knock and announce rule, it might be possible to have the evidence they collected suppressed. This means that any information they obtained in the search could not be used against the occupant in a criminal trial.  

Having evidence suppressed isn't possible in all cases. In Hudson v. Michigan (547 U.S. 586 (2006)) the court ruled that a violation of the knock and announce rule did not necessarily mean the police couldn't use the evidence collected. This was too great of a consequence for a knock and announce violation, according to the court, and it did not serve the purpose of the rule which is to make sure law enforcement behaves reasonably. The Hudson court suggested that if a person's rights were violated by police, his or her legal recourse might include suing the law enforcement agency for a civil rights violation.

This court decision does not, however, mean evidence will never be suppressed if it was collected after police violated the knock and announce rule. If the police behaved in a particularly egregious manner and the court determines that their actions were not reasonable, then the judge might rule to keep evidence out. This decision would be made as part of a criminal trial. For instance, a person accused of a crime would petition the court to have evidence suppressed due to the violation of the knock and announce rule. The judge in that criminal case would hear arguments from both sides and decide whether to consider the collected evidence in deciding guilt or to keep it out because of the civil rights violation.

Different states may also provide different protections for people who have their rights violated by law enforcement entering without knocking. For instance, in Oregon, a knock-and-announce violation can lead to suppression of evidence if the violation is aggravated, although there is little guidance as to what constitutes an aggravated violation (see State v. Bishop, 288 Or. 349 (1980)).

If a knock and announce violation has occurred and incriminating evidence was collected, the person who experienced the unfair treatment should speak with a criminal lawyer to find out whether the evidence may be excluded from consideration in the case.