On this day in 1966, the Supreme Court announced its decision in Miranda v. Arizona. In a decade filled with headline-making Supreme Court rulings, Miranda stood out. It became a favorite target of a conservative law-and-order campaign that helped get Richard Nixon elected president and transformed the politics of criminal justice. But as controversial as the ruling was at the time, Miranda soon became an unlikely popular icon, its requirement that police inform suspects of their rights (“You have the right to remain silent …”) quoted in television shows and movies until it has become part of our cultural firmament.

The case reviewed the criminal convictions of four men, each of whom had confessed to a crime. The lead defendant, Ernesto Miranda signed a written statement confessing to two crimes, a kidnapping and a rape, after two hours of police interrogation. The police had not advised Miranda of his right to have an attorney present during questioning. He was convicted and sentenced to twenty to thirty years in prison.

In a 5-4 ruling, the Court reversed Miranda’s conviction. In the process, the Court extended the Fifth Amendment’s protection against self-incrimination to anyone in police custody. (Prior to this point, this right had only applied at trial.)

Writing for the Court, Chief Justice Earl Warren dedicated much of his lengthy opinion to cataloging the abusive, and often quite brutal, interrogation tactics that had long been common in police departments and that remained prevalent in 1960s America. Such tactics, Warren wrote, were “at odds with one of our Nation’s most cherished principles—that the individual may not be compelled to incriminate himself.”

As a remedy for this constitutional violation, Warren held that for a suspect’s statements to be used at trial, the police first had to inform the suspect of his rights and the consequences of waiving these rights. These rights included: that the suspect had the right to remain silent; that any statement the suspect made could be used as evidence against him; that the suspect has the right to have an attorney present; and that an attorney will be appointed for him if he cannot afford one. Any waiver any of these rights must be “made voluntarily, knowingly and intelligently.”

Warren defended his opinion against the dissenters’ accusations that it would undermine effective law enforcement by noting that the FBI had already implemented a practice of informing suspects and arrestees of their rights before interrogations.

Justice John Marshall Harlan read his strongly worded dissent from the bench. “His face flushed and his voice occasionally faltering with emotion,” reported the Washington Post, Harlan “denounced the decision as ‘dangerous experimentation’ at a time of a ‘high crime rate that is a matter of growing concern.’” Perhaps the most widely reported lines of dissent were those of Justice Byron White, who wrote: “In some unknown number of cases the Court’s rule will turn a killer, a rapist, or other criminal to the streets and to the environment which produced him, to repeat his crime whenever it pleases him.”

Although some praised the decision as an important step in protecting the rights of criminal defendants, much commentary on Miranda predictably echoed the dissenters’ critiques. The ruling “added enormously to the difficulties the Court already has imposed on police,” wrote the conservative New York Times columnist Arthur Krock. He noted that law-enforcement officials already identified the Court’s rulings a primary cause of the increase in crime with which they were dealing. “We might as well close up shop,” declared one police chief said after learning of the ruling.

Despite widespread attacks on the decision, including an effort by Congress to effectively overrule it, the ruling stood and it still stands today, its warnings probably the most recognized—and certainly the most quoted—words ever written in a Supreme Court opinion.