g that illegally seized evidence cannot be used against a defendant at trial. The Court reasoned that the Fourth Amendment was intended to act as a restraint upon the power of federal courts and officials and to protect people against all unreasonable searches and seizures which are carried out "under the guise of law." Allowing such evidence to be presented at trial "would be to affirm by judicial decision a manifest neglect if not an open defiance of the prohibitions of the Constitution, intended for the protection of the people against such unauthorized action...."
For a rather long period of time, the exclusionary rule applied only to federal prosecutions, because the Court did not decide a case concerning the application of the exclusionary rule (through the Fourteenth Amemdment) until 1949. In that year, the Court said that the Fourteenth Amendment prohibited an affirmative state sanction of police incursions into privacy. This prohibition, however, did not authorize the remedy of excluding evidence obtained illegally. The Court said that while the right to be free in one's privacy from arbitrary intrusion by the police, it was not settled that the remedy of excluding evidence obtained during such an intrusion was essential ingredient of this right.
This ruling was eventually reversed by the Court in 1961. In that year, the Court held that the exclusionary rule did apply to the states through the Fourteenth Amendment. The Court noted that since the Wolf decision, a majority of the states had accepted the holding of the Court in Weeks that the exclusionary rule was necessary for the protection against unreasonable searches and seizures. In addition, the Court said that it was good common sense that the exclusionary rule was a vital ingredient in the fourth and Fourteenth Amendments' protection against unreasonable searches and seizures. While a federal prosecutor could not use illegally obtained evidence, a state...