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Making Our Fourth Amendment Right Real: Mapp v. Ohio


After the Bill of Rights was ratified in 1791, it became the responsibility of the new federal government, not the state governments, to ensure these protections for all Americans. More than 100 years later, the Supreme Court started applying some of these rights to the states on a case-by-case basis through the Fourteenth Amendment.

It wasn’t until 1961, however, that the Court applied the Fourth Amendment guarantee against “unreasonable search and seizure” to state governments. The case was Mapp v. Ohio, and it relied on the same rule of evidence used in the 1914 federal case Weeks v. United States, the exclusionary rule. According to this rule, otherwise admissible evidence cannot be used in a criminal trial if it was obtained as the result of illegal conduct by law enforcement officers. The exclusionary rule helped define what is meant by “unreasonable search and seizure.”

This lesson is based on the Annenberg Classroom video “Search and Seizure: Mapp v. Ohio,” which explores the landmark Supreme Court decision that makes state governments also responsible for protecting our Fourth Amendment right. With the exclusionary rule, this right becomes real for all of us.

The estimated time for this lesson is three 50-minute classes.

Download the lesson plan