The 4th Amendment

The 4th Amendment, like the 3rd Amendment, also grew out of colonial practice. It was designed to prevent the use of writs of assistance -blanket search warrants with which British customs officials had invaded private homes to search for smuggled goods.

Each State constitution contains a similar provision. The guarantee also applies to the States through the 14th Amendment’s Due Process Clause. Unlike the 3rd Amendment (the 3rd Amendment has had little importance since 1791 and has never been the subject of a Supreme Court case), the 4th Amendment has proved a highly important guarantee.

Probable Cause

The basic rule laid down by the 4th Amendment is this: Police officers have no general right to search for evidence or to seize either evidence or persons. Except in special circumstances, they must have a proper warrant (a court order). Also, the warrant must be obtained with probable cause -that is, a reasonable suspicion of crime.

Florida v. J . L., 2000, illustrates the rule. There, Miami police had received a tip that a teenager was carrying a concealed weapon. Immediately, two officers went to the bus stop where the tipster said the young man could be found. The police located him, searched him, pulled a gun from his pocket, and arrested him.

The Supreme Court held that the police acted illegally because they did not have a proper warrant. All they had was an anonymous tip, unsupported by any other evidence. Their conduct amounted to just the sort of thing the 4th Amendment was intended to prevent.

Police do not always need a warrant, however–for example, when evidence is “in plain view.” Thus, the Court recently upheld a search and seizure involving two men who were in a friend’s apartment bagging cocaine. A policeman spotted them through an open window, entered the apartment, seized the cocaine, and arrested them. The Court rejected their claim to 4th Amendment protection, Minnesota v. Carter, 1999.

Many 4th amendment cases are complicated. In Lidster v. Illinois, 2004, for example, the Court upheld the use of so-called “informational roadblocks.” In 1997, police had set up one of those barriers on a busy highway near Chicago, hoping to find witnesses to a recent hit-and-run accident.