The FBI didn't need a Miranda exception to question Tsarnaev about ticking bombs

The Tsarnaev case looks like a mirror image of Quarles. On one hand, there was a plausible public-safety rationale for questioning the arrestee before reading him his rights: a fear of unexploded bombs or imminent attacks. On the other hand, excluding the results of the initial interrogation probably would not have a crucial effect on the suspect’s prosecution. But even in cases involving a true emergency where excluding an un-Mirandized confession would make it substantially harder to convict the suspect, the public-safety exception makes no sense if you accept the logic of Miranda v. Arizona. That decision was based on the recognition that questioning someone in police custody is inherently coercive. Unless the arrestee is clearly informed that he is under no obligation to reply, the Court reasoned, the Fifth Amendment guarantee against compelled self-incrimination is apt to be compromised. The wisdom of that safeguard is confirmed by the very expectation that supposedly justifies the public-safety exception: that a suspect will talk more readily if he thinks he has no choice. Fear of ticking bombs may have been a good reason to question Tsarnaev before Mirandizing him. But it is not a good reason to admit what he said in response as evidence against him, because the existence of an emergency does not make police custody any less coercive.