While this series addresses the 4th Amendment, it is important to not confuse the principles with those of other aspects of the Constitution – like the 5th Amendment. Remember that the Miranda Rule is a court-created process where a series of warnings are given prior to an interview of an individual arrested or restrained such that it appears he or she is arrested.
We all walk around with our 4th Amendment rights, whether we are charged with a crime or not. But several right (the right to a jury, the right to an attorney, the right to confront witnesses, and the right against self-incrimination) are rights that apply only if and when there is a criminal trial. As the Miranda Rule is simply an extension of the privilege against self-incrimination, it is a trial right. Since, as the Court said, the violations only apply if the un-Mirandized statement is admitted at trial, the Fruit of the Poisonous Tree Doctrine does not apply to interviews which are not compliant with the requirements of Miranda.
However, if a statement is obtained coercively, then the resulting physical evidence may be suppressed. These principles are best explained from the Supreme Court case dealing with it, U.S. v. Patane. As such, a more detailed legal supplement is attached.
Legal Supplement
In this case we must decide whether a failure to give a suspect the warnings prescribed by Miranda v. Arizona, requires suppression of the physical fruits of the suspect’s unwarned but voluntary statements.
Because the Miranda rule protects against violations of the Self-Incrimination Clause, which, in turn, is not implicated by the introduction at trial of physical evidence resulting from voluntary statements, we answer the question presented in the negative.
As we explain below, the Miranda rule is a prophylactic employed to protect against violations of the Self-Incrimination Clause. The Self-Incrimination Clause, however, is not implicated by the admission into evidence of the physical fruit of a voluntary statement. Accordingly, there is no justification for extending the Miranda rule to this context. And just as the Self-Incrimination Clause primarily focuses on the criminal trial, so too does the Miranda rule. The Miranda rule is not a code of police conduct, and police do not violate the Constitution (or even the Miranda rule, for that matter) by mere failures to warn. For this reason, the exclusionary rule articulated in cases such as Wong Sun does not apply.
The [Self-Incrimination] Clause cannot be violated by the introduction of nontestimonial evidence obtained as a result of voluntary statements.
Our cases also make clear the related point that a mere failure to give Miranda warnings does not, by itself, violate a suspect’s constitutional rights or even the Miranda rule. Our cases also make clear the related point that a mere failure to give Miranda warnings does not, by itself, violate a suspect’s constitutional rights or even the Miranda rule.
It follows that police do not violate a suspect’s constitutional rights (or the Miranda rule) by negligent or even deliberate failures to provide the suspect with the full panoply of warnings prescribed by Miranda. Potential violations occur, if at all, only upon the admission of unwarned statements into evidence at trial.
There is therefore no reason to apply the “fruit of the poisonous tree” doctrine of Wong Sun.
And although it is true that the Court requires the exclusion of the physical fruit of actually coerced statements, it must be remembered that statements taken without sufficient Miranda warnings are presumed to have been coerced only for certain purposes and then only when necessary to protect the privilege against self-incrimination.
Internal Citations Omitted.
