California Supreme Court Imposes Exclusionary Rule on Police
In People v. Cahan, decided on this day, the California Supreme Court upheld the principle of the exclusionary rule, which held that evidence obtained through an unreasonable search and seizure cannot be used against a defendant in court.
The U.S. Supreme Court had imposed the exclusionary rule in federal criminal cases in Weeks v. United Sates, decided on February 24, 1914. The Supreme Court did not apply the rule to state and local police, under the Fourth and Fourteenth Amendments, until the famous case of Mapp v. Ohio, decided on June 19, 1961.
The Cahan decision so outraged Jack Webb, creator and star of the popular television show Dragnet that he devoted an entire Dragnet episode (January 19, 1956) to an attack on the exclusionary rule, making the argument that it turned criminals loose on society. The Mapp decision also outraged police and conservative ideologues nationwide, who made the same argument that Webb had made, and who launched a decades-long campaign against the exclusionary rule. In the decades since 1961, the Supreme Court has created a number of exceptions to the rule, but has never overturned the Mapp decision.
Learn more about the exclusionary rule: Carolyn Long, Mapp v. Ohio: Guarding Against Unreasonable Searches and Seizures (2006)
And learn more about the Fourth Amendment: Stephen J. Schulhofer, More Essential Than Ever: The Fourth Amendment in the Twenty-First Century (2012)