Fourth Amendment Court Cases

Each of these Fourth Amendment Court Cases is somehow significant to the way the Supreme Court has interpreted the Fourth Amendment to the US Constitution. Well, most are significant, some are just interesting! You can read about the history and meaning of the Fourth Amendment here.

4th Amendment Court Cases

Supreme Court
of the United States

Fourth Amendment Court Cases - Mapp vs. Ohio

In a case called Mapp vs. Ohio, 1961, the Supreme Court extended 4th Amendment restrictions to all state governments. Before this time, the 4th Amendment was only applied to the Federal Government.

Fourth Amendment Court Cases - Katz vs. United State

In Katz vs. United States, 1967, a test was established that has been used widely in judging 4th Amendment cases ever since. This is a two part test that defines a legal search according to the 4th Amendment. The test states that the government's actions must not infringe upon the person's subjective expectation of privacy (meaning that it is the individual's opinion that the place or thing to be searched is private), and secondly, that the expectation of privacy is reasonable, meaning that society in general would agree that it is private.

Fourth Amendment Court Cases - Dumbra vs. United States

In Dumbra vs. United States, 1925, the Court defined what is meant by probable cause in the 4th Amendment. The Court ruled that probable cause was a lesser standard than that used to convict a person of a crime. It also said that if the circumstances would "warrant a man of reasonable caution in the belief" that a crime had been committed, then probable cause had been determined. The officer does not have to be correct in his assumption that a crime had been committed, he just has to be reasonably convinced by the facts.

Fourth Amendment Court Cases - Terry vs. Ohio

In Terry vs. Ohio, 1968, the Supreme Court allowed for a pat down search without a warrant if the officer observed suspicious behavior and reasonably believed that a crime was being committed. In this case, the Court said the officer must be able to point to specific facts that led him to this belief.

Read more about the history and meaning of the Fourth Amendment here.

If you would like to read about the meanings of each amendment, go to the First Ten Amendments page here.