“You have the right to remain silent.” You’ve probably heard those words, which are part of the Miranda warning, on countless TV shows following a criminal suspect’s arrest. Thanks to a 1966 landmark ruling by the U.S. Supreme Court in the case of Miranda v. Arizona, the warning—which also lets a person know that anything he says can be used against him in court and that he has a right to an attorney and to have one provided by the state if he can’t afford one—must be given to someone in police custody before he can be questioned. The warning is named for a real person, Ernesto Miranda.

In 1963, Miranda was arrested for the kidnapping and rape of a woman in Phoenix. After being interrogated by law enforcement officials for several hours, he admitted to the crimes then signed a written confession. When Miranda’s case went to trial, his confession was the main evidence used against him. However, his lawyer argued the confession should be tossed out because his client didn’t have an attorney present during questioning and hadn’t fully understood his rights when he confessed—and therefore the confession wasn’t voluntary. The lawyer’s objection was overruled and Miranda was found guilty and sentenced to 20 to 30 years behind bars. The Arizona Supreme Court later upheld his conviction. The U.S. Supreme Court then heard the case and in 1966 ruled 5-4 in favor of reversing Miranda’s conviction, declaring his confession invalid because he hadn’t been informed by police of his constitutional rights. The ruling gave rise to the Miranda warning, which became standard police procedure in the United States, even as it proved controversial, with critics charging it weakened the power of law enforcement to obtain confessions.

In 1967, Ernesto Miranda was retried—this time, without his confession used as evidence—and convicted. After being paroled in 1972, he was stabbed to death four years later in a bar fight.