The United States Supreme Court (SCOTUS) ruled this week that while police must comply with the "knock-and-announce" rule when executing a search warrant, if they fail to, then the evidence can still be used in a court of law. These seem to be contradictory positions, but the issue rests with whether the execution of the warrant, not the issuance of it, was improper. Thus, the question becomes one of procedure over substance and which should predominate.

In 1995, a unanimous Court determined that the common-law rule of police knocking on a person’s door prior to entering a house and executing a search warrant was required in order to comply with the Fourth Amendment’s search and seizure provisions. In other cases, it had been determined that if a search is conducted without probable cause, then the evidence illegally procured had to be suppressed and could not be used in a criminal trial.

Technically, nothing has changed the Fourth Amendment requirements that a police officer must knock prior to executing a search warrant; however, practically, there is no immediate ramification for failure to adhere to this requirement since the evidence obtained as a result of the execution of the warrant can still be used in court. The majority said it can be and several organizations have denounced this decision as a loss of civil liberties. However, it must be determined just what has been lost and whether it was actually a civil liberty prior to the decision.

SCOTUS’s decision does not remove the requirement that the police obtain a warrant prior to entering a house and conducting a search. Thus, prior to the police approaching the house, the police had to show probable cause to a neutral judge in order to obtain the warrant. Once probable cause has been established, the Fourth Amendment’s substantive requirements have been met and only procedural execution of the warrant needs to be conducted. Whether they knock is merely a minor procedural matter that does not diminish the validity of the warrant or the fruits of the search.

This matter can be viewed in a different way as well. When a police officer knocks on a door to execute a warrant a person will presumably answer the door. At that time, the officer will state that he is there pursuant to a warrant to search the house. That person can either voluntarily allow the officer in or deny them entry. If entry is denied, then the officer will force entry and conduct the search anyway. Since the court has already determined that probable cause has been met any search conducted within the parameters of the warrant is valid regardless of whether the home owner acquiesces to the police’s entry.

The SCOTUS dissent stated that the cost of replacing the door and the prevention of a person being surprised by the enforcement of a warrant justify the knock-and-announce rule. Such arguments do not instruct the constitutionality of police actions. Rather the reasonableness of their actions is instructive as to whether they acted within the mandates of the Constitution.

In the end, so long as there is probable cause to conduct a search, the procedure of the execution should not denigrate the evidence procured.