The Supreme Court issued a decision today that a criminal suspect must explicitly tell the law enforcement officers they are going to invoke their Miranda rights during a police investigation. If they speak up to say anything else, police officers will have the lawful right to assume that suspects have waived their rights. The decision, which was 5-4, centered around the case of Van Chester Thompkins, a Michigan man who confessed to a crime three hours into a police interrogation. Police argued that he gave up his right to silence and that his statement could be used in trial against him. Thompson was eventually convicted on the basis of statements he gave to police, but the 6th Circuit Court of Appeals sided with Thompkins and threw out both his confession and conviction. Justice Anthony Kennedy wrote the court’s decision, saying that if a person had been given a Miranda warning and it was clear that the suspect understood their rights, then a person’s "uncoerced" statements should be interpreted as the suspect relinquishing their right to remain silent. Kennedy wrote:

If an ambiguous act, omission, or statement could require police to end the interrogation, police would be required to make difficult decisions about an accused’s unclear intent and face the consequence of suppression ‘if they guess wrong.’ Suppression of a voluntary confession in these circumstances would place a significant burden on society’s interest in prosecuting criminal activity.

Justice Sonia Sotomayor wrote the court’s dissent: "Today’s decision turns Miranda upside down…Criminal suspects must now unambiguously invoke their right to remain silent, which, counterintuitively, requires them to speak." Sotomayor wrote that today’s decision "bodes poorly for the fundamental principles that Miranda protects."