Dzhokhar Tsarnaev, the Boston bombing suspect, remains unable to speak as he undergoes treatment for a gunshot wound to the throat in hospital, officials have said as inquiries focus on what turned two young men into Islamic terrorists…

CBS television quoted investigators as saying that Tsarnaev suffered two serious wounds and had lost a lot of blood. It said investigators had speculated that one wound in the back of his neck could have been a suicide attempt.

“They say it appears from the wound that he might have stuck a gun in his mouth and fired,” said the report, which added that Tsarnaev could understand what those around him were saying.