How did Harris v. New York create an exception to the Miranda rule?

In Harris v. New York (1971), the Supreme Court established an exception to the Miranda rule by ruling that statements obtained from a suspect in violation of Miranda requirements are not automatically excluded from a criminal trial.1

Specifically, the court held that such statements remain admissible for the limited purpose of impeaching the defendant’s credibility if the defendant chooses to testify on their own behalf. This decision marked the beginning of the court's trend of creating exceptions to Miranda, allowing prosecutors to use otherwise inadmissible statements to challenge the truthfulness of a defendant's testimony rather than as direct evidence of guilt.1