In the case of Salinas v. Texas, the United States Supreme Judicial Court recently considered the question of whether a defendant's pre-arrest silence, prior to being placed in custody or receiving Miranda warnings, can be used against him in a subsequent criminal prosecution as evidence of consciousness of guilt.
In this case, prior to being taken into custody, the defendant voluntarily answered some questions from police about a murder. After answering several questions, the defendant remained silent when he was asked whether any ballistic evidence testing would yield matches between his shotgun and the shell casings found at the crime scene. Rather than answer, the defendant remained silent, shuffled his feet, and bit his lip.
After being silent for several moment, he then continued answering other questions from the police.
At trial for murder, the prosecution introduce evidence of the defendant's silence as evidence of consciousness of guilt.
The United States Supreme Judicial Court held that, in circumstances of pre-arrest and where a person has voluntarily chose to speak with police, merely being silent does not automatically assert your 5th Amendment Rights. Rather, the person being questions must expressly invoke the 5th Amendment Protection, i.e., right to remain silent, otherwise it is not invoked and prosecutors may then use that silence against the person at trial.
The court wrote:
"A witness's constitutional right to refuse to answer questions depends on his reasons for doing so and courts need to know those reasons to evaluate the merits of a Fifth Amendment claim..."
In this regard, the U.S. Supreme Court rejected the argument that a person's silence should be understood as a Fifth Amendment plea because most people do not know the law.
The Massachusetts Declaration of Rights, however, offers greater protection to criminal defendants. In similar circumstances, the Massachusetts Supreme Judicial Court has previously suggested that a defendant's pre-arrest silence should not be used as evidence of consciousness of guilt.