The Fifth Amendment to the U.S. Constitution includes this statement: "[no one] shall be compelled in any criminal case to be a witness against himself." This is the right against self-incrimination, a cornerstone of the U.S. justice system. Basically, it means anything a suspect says to police must be voluntary in order to be used against him in court.
Before 1966, "voluntary" was a relatively subjective standard.
In 1963, Phoenix police picked up Ernesto Miranda for questioning in the kidnapping and rape of a young woman. In the course of a two-hour interrogation, Miranda confessed to the crimes. He had not been warned of his right against self-incrimination. His confession was admitted as evidence at trial, and Miranda was convicted and sentenced to 20 to 30 years in prison [source: U.S. Courts].
Miranda v. Arizona was appealed all the way to the Supreme Court, where the central question before the Justices was this: Did the police's failure to warn Miranda of his right to remain silent violate his Fifth Amendment right against self-incrimination, making his confession involuntary and therefore inadmissible at trial?
In a 5-4 decision, the court found that Miranda had in fact been denied his constitutional right, stating, in part:
...the prosecution may not use statements...stemming from custodial interrogation of the defendant unless it demonstrates the use of procedural safeguards effective to secure the privilege against self-incrimination. By custodial interrogation, we mean questioning initiated by law enforcement officers after a person has been taken into custody or otherwise deprived of his freedom of action in any significant way."
The court's decision established a couple of key legal points: that the right against self-incrimination takes effect from the moment a suspect is in police custody, not just at trial; and that any confession obtained without the suspect being explicitly warned of this right is involuntary [source: FindLaw]. Therefore, the court held, a defendant had to be informed of his rights before being interrogated if his statements were to be admissible in court. Since that 1966 ruling, a voluntary confession made in police custody is one preceded by a reading of the Miranda rights:
1. You have the right to remain silent.
2. Anything you say can be used against you in a court of law.
3. You have the right to an attorney.
4. If you can't afford an attorney, one will be appointed for you.
Many law-enforcement agencies throughout the country have since added a fifth warning to the court-established rights, which states, "If you waive these rights, you may still invoke them at a later time" [source: Law and Justice].
And since that ruling, questions have swirled around the law, most of them related to three words in the court's decision: "Taken into custody."