Despite a serious throat wound preventing him from speaking, the surviving Boston Marathon bombing suspect is starting to respond to questions from investigators, federal officials told NBC News. Dzhokhar Tsarnaev, 19, was communicating with federal investigators at the hospital where he is being treated for injuries he acquired following an intense gun battle and manhunt for him and his brother, Tamerlan—the other Boston marathon bombing suspect—who was killed in a firefight with police Friday night. Tsarnaev, who remains in serious condition, has a throat wound, so he responded to questions mostly in writing, according to federal officials who spoke to NBC News on condition of anonymity. The throat wound may be the result of a suicide attempt, investigators said. The special team of federal investigators is hoping to find information on what motivated the Tsarnaev brothers and whether they received any assistance.