By Council on Criminal Justice, Independent Task Force on Policing

In most cases, police seeking to apprehend suspects and recover evidence inside a private home or business are legally required to knock and announce themselves before entering. But the allowable time between knocking and entering may be short. The U.S. Supreme Court has upheld the right of officers to forcibly enter 15 to 20 seconds after announcing their presence, so-called “quick-knock” warrants. In some instances, when it is conceivable that unannounced entry will prevent suspects from fleeing, help preserve evidence, and/or protect the safety of innocent parties or officers, law enforcement requests and judges may issue a “no-knock warrant.” No-knock warrants are often executed in the middle of the night to enhance the element of surprise.

Jurisdictions that prohibit or severely restrict no-knock warrants do so to reduce the risk of harm such surprise intrusions may cause to occupants and officers. Even without a warrant, however, officers may lawfully conduct searches and seizures in the case of emergent exigent circumstances.

Council on Criminal Justice, The independent Task Force on Policing , 2021. 5p.