Silence may be used against you, too.

A defendant who didn’t expressly invoke his privilege against self-incrimination in a voluntary police interview before his formal arrest can have his silence used against him in court, the U.S. Supreme Court has ruled in a fractured decision.

The court ruled in the case of Genovevo Salinas, who had attended a party hosted by two brothers the night before their murders. Salinas voluntarily accompanied officers to the police station and answered their questions until he was asked whether shell casings at the murder scene would match his shotgun. Salinas did not answer. At trial, prosecutors argued that Salinas’ silence suggested he was guilty. Salinas argued that the prosecutors’ remarks violated his Fifth Amendment right against self-incrimination.

Justice Samuel A. Alito Jr. wrote the controlling opinion (PDF), joined by Chief Justice John G. Roberts Jr. and Justice Anthony M. Kennedy. “Petitioner’s Fifth Amendment claim fails because he did not expressly invoke the privilege against self-incrimination in response to the officer’s question,” Alito wrote.

The court had accepted the case to resolve a split of authority on whether prosecutors can use a defendant’s silence at trial, when the defendant’s interview with police takes place before a formal arrest. “But because petitioner did not invoke the privilege during his interview,” Alito said, “we find it unnecessary to reach that question.”

Justice Clarence Thomas, in an opinion joined by Justice Antonin Scalia, said he would rule against Salinas even if he had formally invoked the privilege. The prosecutor did not compel Salinas to give self-incriminating testimony, Thomas said, so Salinas’ claim should fail. “A defendant is not ‘compelled . . . to be a witness against himself’ simply because a jury has been told that it may draw an adverse inference from his silence,” Thomas wrote.

The case is Salinas v. Texas. Hat tip to SCOTUSblog.