For now, the government is invoking the public safety exception, a designation that allows investigators to question Tsarnaev without reading him his Miranda rights, a Justice Department official told CNN on condition of anonymity.
In ordinary cases, a suspect is told by police he has the right to remain silent and he has the right to a lawyer.
But this is not an ordinary case, say U.S. Sens. John McCain and Lindsey Graham.
They urged that Tsarnaev be held as an "enemy combatant," a designation that allows a suspect to be questioned without a lawyer and without being informed of his Miranda rights.