Whether Miranda warnings alone automatically purge the Fourth Amendment taint of a confession obtained after an illegal arrest.
Holding
No. Miranda warnings are important, but they do not by themselves automatically attenuate the taint of an unconstitutional arrest.
Reasoning
The Court distinguished the protections served by the Fourth and Fifth Amendments. Miranda warnings safeguard against compelled self-incrimination during custodial interrogation, but the Fourth Amendment exclusionary rule also aims to deter unlawful searches and seizures and to preserve judicial integrity. A statement may therefore be voluntary under the Fifth Amendment yet still be inadmissible as the product of a Fourth Amendment violation.
Under Wong Sun, the question is not simply whether the statement would have been made but for the illegal arrest. The question is whether police exploited the illegality to obtain the statement or whether intervening circumstances sufficiently dissipated the taint. Treating Miranda warnings as a complete cure would invite officers to make arrests without warrants or probable cause for investigative questioning, confident that warnings could later make any resulting confession usable.
Attenuation must be decided from the facts of each case. Relevant considerations include whether the statement was voluntary as a threshold matter, the time between arrest and confession, intervening circumstances, and especially the purpose and flagrancy of the official misconduct. The prosecution bears the burden of showing that a statement is sufficiently disconnected from the illegal arrest to be admissible.