Brown v. Mississippi, . Law enforcement responded by switching to more subtle techniques, but the courts held that such techniques, even if they do not involve physical torture, may render a confession involuntary and inadmissible. In Chambers v. Florida (1940) the Court held a confession obtained after five days of prolonged questioning, during which time the defendant was held incommunicado, to be coerced. In Ashcraft v. Tennessee (1944), the suspect had been interrogated continuously for thirty-six hours under electric lights. In Haynes v. Washington, the Court held that an "unfair and inherently coercive context" including a prolonged interrogation rendered a confession inadmissible. Miranda v. Arizona (1966) was a landmark case involving confessions. Ernesto Miranda had signed a statement confessing to the crime, but the Supreme Court held that the confession was inadmissible because the defendant had not been advised of his rights. The Court held "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." Custodial interrogation is initiated by law enforcement after a person has been taken into custody or otherwise deprived of his freedom of movement before being questioned as to the specifics of the crime. As for the procedural safeguards to be employed, unless other fully effective means are devised to inform accused persons of their right of silence and to assure a continuous opportunity to exercise it, the following measures are required. Before any questioning, the person must be warned that he has a right to remain silent, that any statement he does make may be used as evidence against him, and that he has a right to the presence of an attorney, either retained or appointed. The warning Chief Justice Earl Warren referred to is now called the Miranda warning, and it is customarily delivered by the police to an individual before questioning. Miranda has been clarified by several further Supreme Court rulings. For the warning to be necessary, the questioning must be conducted under "custodial" circumstances. A person detained in jail or under arrest is, of course, deemed to be in police custody. Alternatively, a person who is under the reasonable belief that he may not freely leave from the restraint of law enforcement is also deemed to be in "custody". That determination of "reasonableness" is based on a totality of the objective circumstances. A