Prosecutors Preparing Charges Against Dzhokhar Tsarnaev
Could face the death penalty
US federal prosecutors are preparing charges against the surviving Boston Marathon bomb suspect Dzhokhar Tsarnaev as more details emerge of his capture.
If he is charged with using a weapon of mass destruction to kill people, he could face the death penalty.
Mr Tsarnaev is in hospital, unable to speak because of a wound to the throat.
US media quoted anonymous sources as saying he had been responding to questions in writing, but this has not been officially confirmed.