The Fourth Amendment provides certain requirements for the manner in which police officers can conduct a search, even if the search is supported by a valid warrant. The general rule is that an officer must announce their presence and their purpose before entering someone’s home. This gives the occupant an opportunity to open the door so that the search can unfold with minimal disruption. If there is no response, the officer must wait for a reasonable time before entering. If the occupant refuses, the officer still has a right to enter, and they can use force if needed. Some state laws have codified this principle.
An announcement can take explicit or implicit forms. For example, an officer might say that they are on the property to execute a search warrant, rather than specifically saying that they are about to enter. Anything that would make their intentions clear to a reasonable person will satisfy a court, so this is not a high standard to meet. The resident cannot argue that they did not hear the officer because they were not in the area. An announcement of their presence meets constitutional requirements, regardless of whether it was actually heard.
An officer usually needs to wait to enter after making the announcement. The length of the waiting period depends on the situation. The officer might not need to wait at all if there is an emergency, such as when they are pursuing a suspect or when they believe that someone in the home is being harmed. Different courts have reached different results in determining the length of time that is reasonable. Moreover, the U.S. Supreme Court has ruled that an officer does not need to announce their presence if they are concerned that the occupants will respond violently or that they will destroy evidence during the waiting period. Following this decision, courts do not apply close scrutiny to potential violations of the knock-notice rule.
Generally, police may not need to follow the knock-notice rule under emergency circumstances, such as when:
The officer is in pursuit of a suspect
The officer believes that someone inside is being harmed
The officer believes that someone inside will react violently
The officer believes that someone inside will destroy evidence
Not every entry is automatically valid, though. A court may find that immediate entry to execute a search warrant is unjustified if it was based solely on the occupants having criminal records.
What Happens After a Violation
A violation of the knock-notice rule does not necessarily have the same consequences as a search that is not supported by probable cause or questioning that is not preceded by Miranda warnings. The Supreme Court has determined that a court does not need to automatically suppress any evidence found after the knock-notice rule is violated. This is because the rule is meant to protect the property and dignity of the occupants, which the Court found to be unrelated to seizing evidence.
However, the laws and constitutions in many states provide more protections than the federal Constitution. Rights provided by the federal government are a floor rather than a ceiling, and states are allowed to go further. Some state courts have ruled that a court does need to suppress any evidence secured after a violation of the knock-notice rule. Other state courts weigh the severity of the violation in determining whether evidence needs to be suppressed. For example, a search in which the police identify their presence but not their purpose may result in suppressing evidence.
Police Behavior Following Entry
After the police enter, they usually will show the warrant to the occupant. If the occupant does not ask to see the warrant, the police are not required to show it.
Police are expected to show respect during a search, but this standard has not been well-defined.
While there is no specific rule for how the police are supposed to behave during a home search, they are expected to show some basic respect to the occupants. If they force an occupant to stand outside for several hours without eating, drinking, or changing their clothes, for example, this may be viewed as an unreasonable search. A court has the discretion to exclude any evidence obtained during an unreasonable search. This decision will depend heavily on the specific facts.