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Exclusionary Rule

Last Updated: 2006

The Fourth Amendment to the U.S. Constitution provides, “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the person or things to be seized.” The unanswered question, however, is what happens to evidence seized due to an unreasonable search or seizure?

The Supreme Court first addressed this issue in the 1914 case of Weeks v. United States. William Robert Weeks Jr. was arrested and charged with sending lottery tickets through the mails. His house was then searched without a warrant, and the papers seized were used in his trial to help convict him. The Court, in reversing the opinion, formulated the exclusionary rule, which holds that evidence obtained through an unreasonable search and seizure cannot be used in a federal court. It was not clear, however, if the exclusionary rule was a necessary part of the Fourth Amendment or simply a rule of evidence formulated by the Supreme Court to be followed by all inferior federal courts.

Furthermore, since Weeks dealt with federal courts, the Court next had to consider the relationship between the Fourth Amendment’s prohibition on unreasonable searches and seizures and the requirements of the Due Process Clause of the Fourteenth Amendment, including the question of the exclusionary rule. In Wolf v. Colorado (1947), the Court held that the right to be free of unreasonable searches and seizures is “fundamental,” and thus incorporated by the Fourteenth Amendment’s Due Process Clause against infringement by the states, but it refused to incorporate the exclusionary rule. Writing for the Court, Justice Felix Frankfurter maintained that considerations of federalism require that the states be given wide latitude in developing remedies for unreasonable searches and seizures committed by their officials.

One consequence of Wolf was that state officials could obtain evidence illegally and then turn it over to federal officials who would use it to convict somebody: the so-called silver platter doctrine. Because the federal authorities had not conducted the illegal search, the evidence was admissible. In the 1960 case of Elkins v. United States, however, the Court held that evidence obtained this way was inadmissible as a Fourth Amendment violation.

The following year, in Mapp v. Ohio, the Court reversed Wolf and held that the Fourth Amendment’s exclusionary rule was now applicable against the states by way of the Due Process Clause of the Fourteenth Amendment. The Court’s rationale was that it was meaningless to give people the right to be free from unreasonable searches and seizures in their states, but then have the states be able to use that evidence to convict. The exclusionary rule, according to the Court, was the only remedy for illegal searches.

Mapp v. Ohio did not end the debate over the exclusionary rule. The Supreme Court, especially under the leadership of Chief Justice Warren Burger but also under his successor, William Rehnquist, fashioned several modifications that limited the scope of the exclusionary rule. For example, in Illinois v. Gates (1983), the Court allowed evidence obtained by a search warrant issued on the basis of an anonymous letter to the police because the police followed the letter with an investigation that supported the information in the letter. The rationale was based on a totality-of-circumstances approach.

In similar fashion, in United States v. Leon (1984), the Court allowed evidence to be used when a warrant was issued based on a tip from a confidential informant of unproven reliability, because the magistrate issuing it was detached and neutral, and the exclusionary rule is meant to deter police. In this case, the police had acted in good faith; it was the magistrate who had erred. Likewise, in the companion case of Massachusetts v. Sheppard, the Court again allowed the evidence when the wrong search warrant was issued by the magistrate. The rationale was the same: the police acted in good faith, and the magistrate made the mistake.

In Arizona v. Evans (1995), the Court allowed evidence to be used even though erroneous information leading to the search resulted from the clerical error of a court employee, who had not deleted a traffic warrant from a computer even though a judge had squelched it. The rationale once more was that the mistake was not made by the police, but by a person who had no stake in the outcome of a particular criminal prosecution.

In Pennsylvania Board of Probation and Parole v. Scott (1998), the Court allowed evidence obtained without a warrant to be used for a parole revocation hearing rather than a criminal trial because the state has an overwhelming interest in ensuring that parolees comply with their parole conditions as they are more likely to commit criminal offenses than are average citizens.

Also in 1998, in Minnesota v. Carter, the Court allowed evidence to be used based on a warrant that was issued after an officer, acting on a tip, had observed drug activity by looking through a gap in closed blinds. The two people convicted did not live in the apartment, and thus the Court reasoned that they could not expect privacy in a place that was not theirs but was simply a place to do business.

The debate about the exclusionary rule continues. On the one side are those who feel that no evidence obtained unreasonably may ever be used in court. On the other side are those who would like to see the rule eliminated, as it allows the guilty to go free on a “technicality.” The end result is a rule that is still in effect but diluted by several decisions of the Supreme Court.

SEE ALSO: Burger, Warren EarlFourteenth AmendmentIncorporation (Nationalization) of the Bill of Rights


James B. Haddad et al., Criminal Procedure (New York: Foundation Press, 1988); Jerold H. Israel, Yale Kamisar, and Wayne R. LaFave, Criminal Procedure and the Constitution (St. Paul, MN: Thomson West, 2003); Irving J. Klein and Christopher J. Morse, Constitutional Law for Criminal Justice Professionals (New York: Looseleaf Law Publications, 2002); and Lloyd L. Weinreb, ed., Leading Constitutional Cases on Criminal Justice (New York: Foundation Press, 2003).