1961 June 19

Exclusionary Rule for the Police: “Mapp v. Ohio”


The Supreme Court on this day ruled, in Mapp v. Ohio, that the Exclusionary Rule applied to state and local police departments. The Exclusionary Rule holds that evidence gained by the police through an unconstitutional search in violation of the Fourth Amendment cannot be used in court against the defendant. The Cleveland police had entered the home of Dolree Mapp on May 23, 1957 without a warrant and, not finding what they originally sought, seized some obscene materials, which which she was eventually convicted.

The Exclusionary Rule was actually nothing new. The Court had applied it to federal law enforcement agencies, in Weeks v. United States, on February 24, 1914. The California Supreme Court, meanwhile, adopted the Exclusionary Rule for that state on April 27, 1955. (Trivia: Jack Webb, creator and star of the hit television show Dragnet was reportedly so incensed by the California Supreme Court’s decision that he developed a program purporting to illustrate is harmful impact on the police.)

Interestingly, in the lower court proceedings, the focus of the lawyers on both sides was on the Ohio obscenity statute, which Mapp’s attorneys hoped to use to invalidate the conviction. The Ohio ACLU and the national ACLU (which filed an amicus brief in the Supreme Court) brought up the issue of the illegal search and seizure and asked the Court to exclude the evidence. At the Supreme Court, one of Justice Earl Warren’s law clerks wrote a memo arguing that “The briefs of the parties in this case are among the worst I have seen all year. Happily, however, the amicus brief of the American Civil Liberties Union and Justice Taft’s opinion in the court below tend to bring the major issues into focus.” (See Long, below, p. 69.)

The Mapp decision touched off a storm of protests by the police and conservative ideologues, who argued that the rule would turn thousands of criminals loose on society. Subsequent research, however, conclusively indicated that very few criminal cases are “lost” as a result of the Exclusionary Rule, and the impact on the crime rate is negligible. In the decades following this decision, the Court has created a number of exceptions to the Exclusionary Rule, weakening it but never completely overturning it.

The Court: “Thus, the State, by admitting evidence unlawfully seized, serves to encourage disobedience to the Federal Constitution which it is bound to uphold.”

Learn more: Carolyn Long, Mapp v. Ohio: Guarding Against Unreasonable Searches and Seizures (2006)

Listen to the oral arguments in the case: http://www.oyez.org/cases/1960-1969/1960/1960_236

Learn more: Stephen Schulhofer, More Essential Than Ever: The Fourth Amendment in the Twenty-First Century (2012)

And about the ACLU role in the Miranda case:  https://www.aclu.org/criminal-law-reform/aclu-history-right-remain-silent

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