Which case established that suspects must be informed of their rights during police questioning?

The case that established the requirement for suspects to be informed of their rights during police questioning is Miranda v. Arizona. This landmark decision by the U.S. Supreme Court in 1966 resulted from the interrogation of Ernesto Miranda, who was not informed of his right to counsel or his right against self-incrimination before being questioned by police.

The ruling emphasized that to protect the Fifth Amendment rights of individuals, law enforcement must inform suspects of their "Miranda rights," which include the right to remain silent and the right to an attorney. This procedural safeguard is intended to ensure that individuals are fully aware of their rights and the implications of waiving them during interrogation, thereby maintaining the integrity of the criminal justice process.

This principle has become a fundamental aspect of police procedures in the United States, ensuring that confessions or statements made by suspects are both voluntary and informed, protecting individuals from potential abuses during custodial interrogation.