The right of an accused person to remain silent (and not be forced to testify against oneself) is a fundamental right under the Fifth Amendment to the United States Constitution. The Fifth Amendment states, in part, that no person “shall be compelled in any criminal case to be a witness against himself.”

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 right of an accused person to remain silent and not be compelled to testify against oneself is protected under the Fifth Amendment to the United States Constitution. This right is a cornerstone of American criminal procedure and is strictly observed. The Miranda warnings, stemming from the U.S. Supreme Court's decision in Miranda v. Arizona, require that individuals in police custody be informed of their rights before any custodial interrogation begins. These rights include the right to remain silent, the right to consult with an attorney, and the right to have an attorney present during questioning. If an individual cannot afford an attorney, one must be provided at no charge. In Texas, if a person does not voluntarily waive these rights, any evidence obtained during a custodial interrogation may be deemed inadmissible under the exclusionary rule. This rule also applies to any secondary evidence that is a direct result of an illegal interrogation, known as 'fruit of the poisonous tree.' However, there are exceptions to this rule, such as the good-faith exception, the independent source doctrine, the inevitable discovery doctrine, the attenuation doctrine, and the use of evidence for impeachment purposes. Texas courts adhere to these federal constitutional protections and the associated case law when adjudicating criminal cases.