The Supreme Court issued a ruling today in Salinas v. Texas, a case about whether or not the prosecution can use pre-arrest silence as evidence of guilt. In general, the prosecution cannot use a defendant's invocation of his Fifth Amendment right, the right to remain silent, as evidence of his or her guilt. In Salinas, the defendant was out-of-custody, voluntarily answering police questions at the police station. When asked about potentially incriminating evidence, Salinas remained silent. During his trial, the prosecution argued that his silence was evidence of guilt. The Supreme Court ruled that the Fifth Amendment right only applies when the suspect invokes the right, and silence, apparently, does not invoke a right to silence.
For more on Salinas, see Lyle Denniston, Opinion recap: If you want to claim the Fifth . . ., SCOTUS blog (Jun. 17, 2013, 5:42 PM),