Today, the U.S. Supreme Court handed down its third ruling this year interpreting the nuances of Miranda v. Arizona, 384 U.S. 436 (1966). In Berghuis v. Thompkins, 560 U.S. ___ (2010), the Court held that, “A suspect who has received and understood the Miranda warnings, and has not invoked the Miranda rights, waives the right to remain silent by making an uncoerced statement to the police.”
Van Chester Thompkins was a suspect in the murder of Samuel Morris outside a strip mall in Southfield, Mich. When the police brought him in for questioning he was advised of his right to remain silent and his right to legal counsel. He remained mostly silent for nearly three hours. As a result of his silence he failure to acknowledge that he was willing to talk or that he wanted to end the interrogation.
The police continued to interview Thompkins. After three hours he was asked, "Do you pray to God to forgive you for shooting that boy down?" Thompkins answered, "Yes." The statement was used against him at trial.
Justice Anthony M. Kennedy wrote on behalf of a 5 to 4 majority, "If Thompkins wanted to remain silent, he could have said nothing in response to [the detective's] questions, or he could have unambiguously invoked his Miranda rights and ended the interrogation."
The Court made it clear that anything short of an unequivocal response either waiving or invoking the right to silence or counsel will not be sufficient. Silence itself is not enough to claim the right to remain silent.
Justice Sonia Sotomayor, wrote a dissenting opinion taking issue with the majority opinion, "Criminal suspects must now unambiguously invoke their right to remain silent, which, counterintuitively, requires them to speak."
The full opinion: http://www.supremecourt.gov/opinions/09pdf/08-1470.pdf