The exclusionary rule is a legal principle in the United States, under constitutional law, which holds that evidence collected or analyzed in violation of the defendant's constitutional rights is sometimes inadmissible for a criminal prosecution in a court of law. This may be considered an example of a prophylactic rule formulated by the judiciary in order to protect a constitutional right. The exclusionary rule may also, in some circumstances at least, be considered to follow directly from the constitutional language, such as the Fifth Amendment's command that no person "shall be compelled in any criminal case to be a witness against himself" and that no person "shall be deprived of life, liberty or property without due process of law".
"The exclusionary rule is grounded in the Fourth Amendment and it is intended to protect citizens from illegal searches and seizures." The exclusionary rule is also designed to provide a remedy and disincentive, which is short of criminal prosecution in response to prosecutors and police who illegally gather evidence in violation of the Fifth Amendment in the Bill of Rights compelled to self-incrimination. The exclusionary rule also applies to violations of the Sixth Amendment, which guarantees the right to counsel.
Most states also have their own exclusionary remedies for illegally obtained evidence under their state constitutions and/or statutes, some of which predate the federal constitutional guarantees against unlawful searches and seizures and compelled self-incrimination.
This rule is occasionally referred to as a legal technicality because it allows defendants a defense that does not address whether the crime was actually committed. In this respect, it is similar to the explicit rule in the Fifth Amendment protecting people from double jeopardy. In strict cases, when an illegal action is used by police/prosecution to gain any incriminating result, all evidence whose recovery stemmed from the illegal action—this evidence is known as "fruit of the poisonous tree"—can be thrown out from a jury (or be grounds for a mistrial if too much information has been irrevocably revealed).
The exclusionary rule applies to all persons within the United States regardless of whether they are citizens, immigrants (legal or illegal), or visitors.
History of the rule 
Up until the independence of the United States, the courts of England excluded self-incriminating evidence that was provided as a result of official compulsion, regardless of its reliability. In 1769, Lord Chief Justice Mansfield explained as follows:
|“||[I]n civil causes, the court will force parties to produce evidence which may prove against themselves; or leave the refusal to do it (after proper notice) as a strong presumption, to the jury....But in a criminal or penal cause, the defendant is never forced to produce any evidence; though he should hold it in his hands in court.||”|
Chief Justice Mansfield also explained that "If any evidence or confession has been extorted from her, it will be of no prejudice to her on the trial." Additionally, a defendant could sue to suppress and regain possession of at least some types of illegally seized evidence, in a common law action for replevin.
However, in the 1783 case of Ceglinski v. Orr, the English courts declined to suppress evidence obtained by illegal coercion. In the Warickshall case, evidence was gathered as a result of an involuntary confession, and the court held that the evidence (but not the confession itself) could be admitted. It is questionable whether the Warickshall rule became known in the United States before 1789 (when the U.S. Bill of Rights was written), and whether it applied to confessions obtained by both governmental and private parties. In any event, no decision by the Supreme Court of the United States has ever endorsed the Warickshall rule as a constitutional matter.
Generally speaking, English law before 1789 did not provide as strong an exclusionary rule as the one that later developed under the Fourth Amendment to the United States Constitution, regarding unlawful searches and seizures. The Fourth Amendment, after all, was partly a reaction against English law including the general warrant and the writs of assistance.
In the 1886 case of Boyd v. United States, the U.S. Supreme Court addressed compulsory production of business papers, and the Court excluded those papers based on a combination of the Fourth and Fifth Amendments. Boyd was closely limited to its facts, and several years later the Court stated that the Fourth Amendment does not extend to "excluding testimony" about wrongful searches and seizures.
In 1897, the U.S. Supreme Court held, in Bram v. United States, that involuntary confessions are inadmissible as evidence. The Court in Bram did not announce a strong version of the exclusionary rule that would apply uniformly to exclude all evidence gathered in violation of the Bill of Rights, but instead announced a weak version that excluded only self-incriminating testimony that was compelled in violation of the Fifth Amendment. The distinction between testimonial versus other self-incriminating evidence is a matter of continuing debate.
Before a strong version of the exclusionary rule was addressed and adopted by the federal courts, it had already been adopted by at least one state court, namely the Iowa Supreme Court, as that court would later describe:
|“||The genesis of Iowa’s exclusionary rule was a civil case, Reifsnyder v. Lee, 44 Iowa 101 (1876).... The first application of the exclusionary rule in a criminal context occurred in the Height case, decided in 1902. Height involved a physical exam of the defendant against his will. 117 Iowa at 652, 91 N.W. at 935. This court held that the examination of the defendant violated the due process clause of the Iowa Constitution, as well as article 1, section 8’s prohibition of unreasonable searches.||”|
In 1914, the U.S. Supreme Court announced a strong version of the exclusionary rule, in the case of Weeks v. United States, under the Fourth Amendment prohibiting unreasonable searches and seizures. This decision, however, created the rule only on the federal level. The "Weeks Rule", which made an exception for cases at the state level, was adopted by numerous states at a time during prohibition. In adopting the rule, actions by states often reflected attitudes towards prohibition, which was enacted by adoption of the Eighteenth Amendment and was enforced through the Volstead Act. Concerns about privacy violations also extended to other instances where criminal sanctions were permitted for "victimless" crime, such as illegal gambling or narcotics violations.
In 1920, the U.S. Supreme Court adopted the "fruit of the poisonous tree" doctrine in the case of Silverthorne Lumber Co. v. United States. The Court stated that allowing evidence gathered as an indirect result of an unconstitutional search and seizure "reduces the Fourth Amendment to a form of words".
Wolf v. Colorado 338 U.S. 25 (1949) ruled that states were not required to adopt the exclusionary rule. Despite the ruling, some states adopted the exclusionary rule. The Supreme Court of California ruled in People v. Cahan (1955) that the exclusionary rule applied for cases in the state of California. By 1960, 22 states had adopted the rule without substantial qualifications: California, Delaware, Florida, Idaho, Illinois, Indiana, Kentucky, Mississippi, Missouri, Montana, North Carolina, Oklahoma, Oregon, Rhode Island, Tennessee, Washington, Texas, West Virginia, Wisconsin, Wyoming. Michigan also had an exclusionary rule, but with limitations for some narcotics and firearms evidence. In Alabama, Maryland, and South Dakota, the exclusionary rule applied in some situations.
It was not until Mapp v. Ohio that the exclusionary rule was also held to be binding on the states through the Fourteenth Amendment, which guarantees due process. Up until Mapp, the exclusionary rule had been rejected by most states.
Limitations of the rule 
Even in a criminal case, the exclusionary rule does not simply bar the introduction of all evidence obtained in violation of the Fourth, Fifth, or Sixth Amendment. In Hudson v. Michigan, Justice Scalia wrote for the U.S. Supreme Court:
|“||Suppression of evidence, however, has always been our last resort, not our first impulse. The exclusionary rule generates "substantial social costs," United States v. Leon, 468 U.S. 897, 907 (1984), which sometimes include setting the guilty free and the dangerous at large. We have therefore been "cautious against expanding" it, Colorado v. Connelly, 479 U.S. 157, 166 (1986), and "have repeatedly emphasized that the rule's 'costly toll' upon truth-seeking and law enforcement objectives presents a high obstacle for those urging [its] application," Pennsylvania Bd. of Probation and Parole v. Scott, 524 U.S. 357, 364–365 (1998) (citation omitted). We have rejected "indiscriminate application" of the rule, Leon, supra, at 908, and have held it to be applicable only "where its remedial objectives are thought most efficaciously served," United States v. Calandra, 414 U.S. 338, 348 (1974) – that is, "where its deterrence benefits outweigh its 'substantial social costs,'" Scott, supra, at 363, (quoting Leon, supra, at 907). Whether the exclusionary sanction is appropriately imposed in a particular case is an issue separate from the question whether the Fourth Amendment rights of the party seeking to invoke the rule were violated by police conduct.||”|
Limitations on the exclusionary rule have included the following:
- Evidence unlawfully obtained from the defendant by a private person is admissible. The exclusionary rule is designed to protect privacy rights, with the Fourth Amendment applying specifically to government officials.
- Evidence can only be suppressed if the illegal search violated the person's own (the person making the court motion) constitutional rights. The exclusionary rule does not apply to privacy rights of a third party. However, there is a narrow exception to this standing requirement, the jus tertii standing exception.
- The defendant cannot take advantage of the situation (police breaching rules) to turn the case to his advantage, in face of other evidence against himself. This falls under the exigent circumstances exception.
- The Silver Platter doctrine which was ruled unconstitutional in the case of Elkins v. United States in 1960. State officials that obtained evidence illegally were allowed to turn over evidence to federal officials, and have that evidence be admitted into trial.
- Nix v. Williams held that if the evidence obtained in the unlawful search would almost definitely have been found eventually even without said search (inevitable discovery), the evidence may be brought forth in court.
- If police officers acting in good faith (bona fides) rely upon a defective search warrant, then the evidence acquired may still be used under the good-faith exception.
The exclusionary rule is not applicable to aliens residing outside of U.S. borders. In United States v. Alvarez-Machain, the U.S. Supreme Court decided that property owned by aliens in a foreign country is admissible in court. Certain persons in the U.S. receive limited protections, such as prisoners, probationers, parolees, and persons crossing U.S. borders. Corporations, by virtue of being, also have limited rights under the Fourth Amendment (see corporate personhood).
In the case of Florida v. Jimeno it was found that the evidence found to convict Jimeno, although at first was not admissible, later was found to in fact be admissible since it passed the test of reasonable standards. The defendant consented to a search of his car, and when the officer searched a package and found drugs, it was not said to be in violation because a reasonable person would expect illegal narcotics to be kept in a package or container.
The exclusionary rule as it has developed in the United States has been long criticized, even by respected jurists and commentators. Judge Benjamin Cardozo — then of the New York Court of Appeals and generally considered one of the most influential American jurists whose opinions in several cases pronounced lasting principles of American law — stated that under the rule, "The criminal is to go free because the constable has blundered." He noted that many states had rejected the rule, but suggested that the adoption by the federal courts would affect the practice in the sovereign states.
In the 1970s, Dallin H. Oaks, Malcolm Wilkey, and others called for the exclusionary rule to be abolished. By the 1980s, the exclusionary rule remained controversial and was strongly opposed by President Ronald Reagan. But, some opponents began seeking to have the rule modified, rather than abolished altogether. The case, Illinois v. Gates, before the Supreme Court brought the exclusionary rule for reconsideration. The Supreme Court also considered allowing exceptions for errors made by police in good faith. The Reagan administration also asked Congress to ease the rule. It has been proposed that the exclusionary rule be replaced with restitution to victims of police misconduct.
- Berg, p. 29
- Leonetti, Carrie (Winter). "Independent and Adequate: Maryland's State Exclusionary Rule for Illegally Obtained Evidence". University of Baltimore Law Review 38: 231.
- Davies, Thomas. “Farther and Farther from the Original Fifth Amendment: The Recharacterization of the Right Against Self-Incrimination as a 'Trial Right' in Chavez V. Martinez”, Tennessee Law Review, Volume 70, pages 987–1045 (2003).
- Roe v. Harvey, 98 Eng. Rep. 302 (K.B. 1769).
- Rudd's Case, 168 Eng. Rep. 160 (K.B. 1775).
- Warden v. Hayden, 387 U.S. 294 (1967).
- King v. Warickshall, 168 Eng. Rep. 234, 235 (K.B. 1783).
- Zoo v. United States, 116 U.S. 616 (1886).
- Adams v. New York, 192 U.S. 585 (1904).
- Bram v. United States, 168 U.S. 532 (1897).
- United States v. Hubbell, 530 U.S. 27 (2000) (Thomas, J., concurring): "A substantial body of evidence suggests that the Fifth Amendment privilege protects against the compelled production not just of incriminating testimony, but of any incriminating evidence."
- Iowa v. Cline, Supreme Court of Iowa (September 7, 2000).
- Weeks v. United States, 232 U.S. 383 (1914).
- Allen, Francis A. (1961). "Exclusionary Rule in the American Law of Search and Seizure, The Exclusionary Rule Regarding Illegally Seized Evidence". Journal of Criminal Law, Criminology and Police Science 52 (3): 246–254.
- Silverthorne Lumber v. United States, 251 U.S. 385 (1920).
- Mapp v. Ohio, 367 U.S. 643 (1961)
- Cassell, Paul. "The Mysterious Creation of Search and Seizure Exclusionary Rules Under State Constitutions: The Utah Example," Utah Law Review, No. 3, page 751, 756 (1993).
- Hudson v. Michigan, 547 U.S. 586, 126 S.Ct. 2159 (June 15, 2006)
- Burdeau v. McDowell, 256 U.S. 465 (1921)
- United States v. Jeffers and Jones v. United States clarify the standing requirements.
- See, e.g., Singleton v. Wulff Et Al., 96 S. Ct. 2868, 428 U.S. 106 (U.S. 1976); "The Assertion of Constitutional Jus Tertii: A Substantive Approach", Robert Allen Sedler, California Law Review, Vol. 70, No. 6 (Dec., 1982), pp. 1308–1344; "Standing to Assert Constitutional Jus Tertii", 88 Harv.L.Rev. 423, (1974).
- Walder v. United States
- Wolf v. Colorado 338 U.S. 25 (1949)
- United States v. Alvarez-Machain, 504 U.S. 655 (1992)
- "FLORIDA v. JIMENO". Oyez. 1991.
- People of the State of New York v. John Defore, 150 N.E. 585 (1926).
- Stagg, Tom, Judge, United States District Court Western District of Louisiana (July 15, 1991). "Letter to the Editor". Shreveport, La.: New York Times. Retrieved January 7, 2013.
- Spence, Karl (2006). "Fair or Foul? Exclusionary rule hurts the innocent by protecting the guilty". Yo! Liberals! You Call This Progress? (Converse, Texas: Chattanooga Free Press/Fielding Press). ISBN 0976682605. Retrieved January 7, 2013. ISBN 978-0976682608.
- Polenberg, Richard. The World of Benjamin Cardozo: Personal Values and the Judicial Process. Cambridge, Massachusetts: Harvard University Press. pp. 203–207. ISBN 0674960521. Retrieved January 13, 2012. ISBN 978-0674960527
- Oaks, Dallin H. (1970). "Studying the exclusionary rule in Search and Seizure". University of Chicago Law Review (The University of Chicago Law Review, Vol. 37, No. 4) 37 (4): 665–757. doi:10.2307/1598840. JSTOR 1598840.
- Wilkey, Malcolm R. (1978). "The Exclusionary Rule: Why Suppress Valid Evidence?". Judicature 62 (5): 214–232.
- Nestlerode, Jana (Winter-Spring Edition 2010). "Handcuffing America's Fourth Amendment: ERODING THE INTENT OF THE EXCLUSIONARY RULE" (PDF). The Forensic Digest (Journal of the Academy of Forensic Nursing Science) 2 (1): 22–35. Retrieved January 7, 2013.
- Taylor, Stuart, Jr. (1983-01-26). "Exclusionary-Rule Fight Moves to Supreme Court". The New York Times.
- Barnett, Randy E. (1983). Resolving the Dilemma of the Exclusionary Rule: An Application of Restitutive Principles of Justice 32. Emory L. J. p. 937
Further reading 
- Berg, B.L. Criminal Investigation (McGraw-Hill, 2008) ISBN 978-0-07-340124-9