Does the 'right to remain silent' require silence or 'magic words'?

On Wednesday, the US Supreme Court heard oral arguments in Salinas v. Texas (see prior Grits coverage) in which the Texas Court of Criminal Appeals ruled that prosecutors may argue that silence in response to questioning demonstrates guilt if the questions were asked prior to the defendant being taken into custody and read their Miranda rights. Here's a link to the transcript (pdf) and the TXCCA opinion being challenged.

At SCOTUSBlog, Lyle Dennistron suggested that, "If the sentiment that seems to run high in a Supreme Court hearing dictated how a case would come out, the Justices might well be on their way to declaring that the Constitution forbids prosecutors from telling juries that a suspect’s silence when talking to police in any criminal investigation means he is guilty."

In technical legal terms, [Stanford Law Prof. Jeffrey] Fisher was arguing that, in the pre-arrest context, when an individual is being questioned, the suspect should not have to explicitly claim the Fifth Amendment privilege in order to keep his silence in response to a damaging question from being used against him.

The state of Texas, with the support of the federal Department of Justice, told the Court that in no situation before trial should the Fifth Amendment privilege apply unless the individual explicitly, or by strong implication, says something to claim that right.   While no prior precedent of the Court settles whether the Fifth Amendment does or does not apply in that circumstance, the Texas lawyer at the lectern Wednesday, Alan K. Curry, encountered a largely skeptical Court in reaction to his plea for such a flat limitation of Fifth Amendment rights.

Curry argued that, if an individual does not invoke the Fifth Amendment, then silence in response to a specific police question about the crime should be open to the prosecutor to use against the individual at the trial.

The debate seemed to center on whether a defendant must specifically utter "magic words" to invoke their Fifth Amendment right or whether merely exercising the right, as opposed to invoking it, is enough to secure the privilege. Fisher argued that requiring such magic words amounts to "nothing more than a trap for the unwary, who is told, through culture and learning, that he has a right to remain silent." Mr. Salinas, he said, did the "one thing that is consistent with his right, which is exercising it," and so the state should not be able to "walk into court and say, because he remains silent, he's guilty of a crime; jury, you should conclude he's guilty of a crime."

That's exactly what happened in this case. Police questioned Salinas for nearly an hour about other possible suspects, but he turned mute and refused to answer once they began asking questions that indicated they considered him a suspect, in particular whether ballistics would match a shotgun he owned to shell casings found at the crime scene. Here's an excerpt from the Harris County prosecutor's closing argument that's in dispute:

The police officer testified that he wouldn’t answer that question. . . . You know, if you asked somebody – there is a murder in New York City, is your gun going to match up the murder in New York City? Is your DNA going to be on that body or that person’s fingernails? Is [sic] your fingerprints going to be on that body? You are going to say no. An innocent person is going to say: What are you talking about? I didn’t do that. I wasn’t there. He didn’t respond that way. He didn’t say: No, it’s not going to match up. It’s my shotgun. It’s been in our house. What are you talking about? He wouldn’t answer that question. 

If the the defendant had either a) been in custody or b) expressly stated "I invoke my Fifth Amendment right to remain silent," even the state granted that the prosecution's closing argument would have been improper. The state's argument hinged on a distinction between custodial and non-custodial interrogations, hanging their hats on the fact that past SCOTUS precedents dealt solely with questioning while in police custody.

In a preview of the case, SCOTUSBlog laid out (and linked to) the key court precedents relied upon by the state, but as Mr. Fisher pointed out those were instances where the defendants' silence on particular questions was used to impeach their testimony after they'd chosen to take the stand at trial. I hope Denniston is correct in his tea-leaf reading and SCOTUS extends Fifth Amendment protections to pre-custodial interrogations. IANAL but the idea seems like a no-brainer to me.