No-Knock Warrant

A no-knock warrant is a search warrant authorizing police officers to enter certain premises without first knocking and announcing their presence or purpose prior to entering the premises. Such warrants are issued where an entry pursuant to the knock-and-announce rule (ie. an announcement prior to entry) would lead to the destruction of the objects for which the police are searching or would compromise the safety of the police or another individual.

According to the Department of Justice, "Although officers need not take affirmative steps to make an independent re-verification of the circumstances already recognized by a magistrate in issuing a no-knock warrant, such a warrant does not entitle officers to disregard reliable information clearly negating the existence of exigent circumstances when they actually receive such information before execution of the warrant."

See Search Warrants, Fourth Amendment.