In Simmons v. United States, the U.S. Supreme Court rules that when a criminal defendant chooses to testify at a pretrial hearing about certain evidence (which the defendant alleges was gathered by police in violation of the Fourth Amendment’s search and seizure provision), that testimony – even if it is incriminating – cannot later be used against the defendant at trial. Otherwise, the court states, a defendant will be forced to choose between exercising his Fourth Amendment right (to try to suppress illegally obtained evidence) or his Fifth Amendment right (to refuse to give testimony against himself).