The exclusionary rule is a judge made rule designed to discourage violations of the fourth amendment to the constitution that guarantees every individual to be free from unreasonable searches and seizures. If an individual is aggrieved by an illegal search and seizure, anything that the cops find pursuant to that search will not be permitted to be used against the accused. Since the cops know that, they will not conduct illegal searches because they will not be able to use the evidence anyway. The evidence will be “excluded,” thus the term, “exclusionary rule.”
The knock and announce rule says that police officers must knock and announce their presence, allowing the homeowner or tenant a reasonable time to open the door before they barge in. This rule does not apply where exigent circumstances exist, where, for example, the people inside are destroying evidence or pose a danger because the cops know they are armed. Thus, where surprise is needed, no need to observe the knock and announce rule.
In a case before the court of appeals for the second circuit, the court found that if the knock and announce rule is violated, there is no need to suppress or exclude the evidence from being used. This is because the rule has no bearing on the reasonableness of the search, only on how the search is conducted. Because it does not violate the accused’s right to be free from unreasonable search and seizure, the exclusionary rule would not prevent illegal searches.
This is a curious case because every man’s home has for centuries been considered his castle, and as lord of his castle he has a right to expect that the cops will respect him enough to permit him to open the door and voluntarily let them in. Dignity was important to the founders of this country, and for a long time the exclusionary rule did apply to violations of the knock and announce rule.
Dignity has been found to be the touchstone to another constitutional right, the right against self-incrimination. There were competing interests involved. One is the search for the truth. The other is the lack of dignity involved in requiring a man to incriminate himself. The founders of the country opted for dignity, and so the right to remain silent and not incriminate oneself was created. True, this right is found in the U.S. constitution and the knock-and-announce rule is not, but dignity is so important that whenever it is threatened, the severe sanction of rendering whatever evidence is seized should be imposed. US v. Carvajal , 2d circuit, decided September 5, 2007.