The Bill of Rights, which includes the Fifth and Sixth Amendments, was written and added to the Constitution. The Fifth guarantees the right of no self-incrimination: no person "shall be compelled in any criminal case to be a witness against himself." The Sixth provides for an attorney for any defendant in a criminal case (among other protections during trial).
In this Supreme Court case, a confession of guilt by Ziang Sun Wan was dismissed because the confession was forced. This set the precedent that confessions must be voluntary, per the Fifth Amendment. Foreshadowing, anyone?
No money? No problem. Clarence Gideon couldn't afford a lawyer to defend him in court, and he was forced to act as his own counsel. As savvy Shmoopers know, thanks to the Sixth Amendment, everyone gets to have a lawyer, poor or rich or somewhere in between. This Supreme Court case set the precedent that the state would provide a lawyer if you couldn't afford one.
Miranda was arrested by the Phoenix Police Department. He had been accused of kidnapping and raping an 18-year-old woman ten days prior. Miranda was placed in custody, was interrogated for two hours, and signed a confession to the charges.
At Miranda's first trial, he was appointed a lawyer named Alvin Moore. Moore objected to using Miranda's confession in court (because, he argued, Ernesto was never told his rights to silence or an attorney), but the judge overruled his objection. Miranda was convicted of rape and kidnapping and sentenced to 20-30 years in prison.
This Supreme Court case set the precedent that criminal suspects have a "right to counsel" (i.e., the right to have a lawyer present) during police interrogations. Decades later, all of America would learn this on reruns of Law & Order.
After failing to get the decision reversed by the Arizona Supreme Court, Miranda and his lawyer appealed to the big guns: the United States Supreme Court. Alvin Moore stepped down as Miranda's lawyer, and John Flynn took over. Flynn wrote an argument saying that Miranda's Fifth Amendment rights had been violated.
SCOTUS agreed to hear Miranda's case in November 1965, and had a decision by June of the following year. Earl Warren's final opinion was released on June 13th, 1966. After that point, Miranda Warning cards were required of all police officers across the nation.
Although Miranda v. Arizona worked out in Ernesto's favor, he was brought back to trial with other (non-confession) evidence. He was again found guilty of his crimes, and sentenced to 20-30 years in prison. So…yeah.
The finalized text for the Miranda Warning was completed, sent out to all police agencies in the country, and officially required.
Miranda was paroled and returned to a life of petty crime. He was arrested for some driving offenses and for possession of a gun. Not the brightest bulb in the box.
At a bar in Phoenix, a violent fight broke out. Miranda was stabbed, and he died on January 31st. His killer was never arrested. (Source)