The terms Miranda warnings or Miranda rights refer to the requirement that the police inform a person in police custody (whose freedom is deprived in any significant way)—and who the police also seek to interrogate (known as custodial interrogation)—of certain rights, to ensure the person’s privilege against self-incrimination and right to counsel, as provided in the Fifth and Sixth Amendments to the United States Constitution.

Miranda warnings have been required by the United States Supreme Court since its decision in the landmark case of Miranda v. Arizona, 384 U.S. 436 (1966). In the Miranda case, the Court held that a person cannot be questioned by the police in a custodial interrogation until the person is informed of (1) the person’s right to remain silent; (2) the person’s right to consult with an attorney and to have the attorney present during questioning; and (3) the person’s right to be appointed an attorney at no charge if the person cannot afford an attorney.

A person may voluntarily waive these Miranda rights after being informed of them, and agree to talk to the police without consulting with an attorney or having an attorney present during the questioning. But unless a person voluntarily waives these rights, any evidence the police discover from a custodial interrogation—directly or indirectly—will not be admissible in evidence in a criminal prosecution against the person. This rule of evidence is known as the exclusionary rule, and it extends to evidence the police would not have uncovered without the illegal interrogation—and such derivative evidence is known as the fruit of the poisonous tree.

There are exceptions to the exclusionary rule—including (1) the good-faith exception; (2) the independent source doctrine; (3) the inevitable discovery doctrine; (4) the attenuation doctrine; and (5) impeachment evidence.

In Texas, as in all states, the Miranda warnings are a critical component of police procedure, stemming from the U.S. Supreme Court's decision in Miranda v. Arizona. These warnings are designed to protect an individual's Fifth Amendment right against self-incrimination and Sixth Amendment right to counsel. When a person is in police custody and subject to interrogation, they must be informed of their right to remain silent, their right to consult with an attorney and have the attorney present during questioning, and their right to have an attorney appointed at no cost if they cannot afford one. If these rights are not communicated, or if the individual does not voluntarily waive them, any evidence obtained as a result of the custodial interrogation may be inadmissible in court under the exclusionary rule. This rule also applies to any secondary evidence that would not have been discovered without the initial illegal interrogation, known as 'fruit of the poisonous tree.' However, there are exceptions to the exclusionary rule, such as the good-faith exception, independent source doctrine, inevitable discovery doctrine, attenuation doctrine, and the use of evidence for impeachment purposes. An attorney can provide guidance on how these rights and exceptions may apply in a specific case in Texas.