Fourth Amendment to the U.S. Constitution

The right of the People to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized. 

The Fourth Amendment to the U.S. Constitution is the main limitation on the government’s police powers set forth in the Constitution.  Part of the original Bill of Rights, it derives from the Founding Father’s vehement opposition to the abusive general warrants used by British officials during the period leading up to the American Revolution.  The Fourth Amendment originally only limited the federal government but was applied to the states (“incorporated” into the Fourteenth Amendment’s due process clause) by the Supreme Court in Mapp v. Ohio (1961).  Because the Fourth Amendment is implicated in essentially every interaction between government and citizens, it has been the source of more litigation, both criminal and civil, than any other constitutional provision.  The legal doctrines, tests, rules, and exceptions applicable to the Fourth Amendment are enormous in scope and complexity.  Although some issues are straightforward, the Fourth Amendment is one of the most challenging areas of the law.