i'm jonathan mann. >> and i'm isha sesay. >> the surviving suspect in the boston terror attack is starting to tell authorities what he knows. >> dzhokhar tsarnaev had indicated to investigators that his now deceased older brother was the driving force and no international terrorist groups were involved in the attack. three people were killed and more than 170 were injured. >> a sign of a city moving forward after a week of combing the street where the bombs went off. other streepts around the bomb site remain closed while officials make sure nearby buildings are safe. >>> the court case geagainst tsarnaev. this was an important day for the court case and the investigation. tsarnaev is talking to authorities. they are talking back. what are both sides saying? >> reporter: let's clear up one thing. he is not doing much talking. he is nodding. he is able to communicate with authorities but he can barely speak because he suffered very serious wounds including to the throat. he was able to say no at one point during his bed side h

i'm jonathan mann. >> and i'm isha sesay at cnn center in atlanta. coming up this hour, questions and answers. the boston bombing suspect communicating with the feds on the driving forces behind the city's marathon attacks. >> cheap, easy, and extremely dangerous. the lethal combination behind the pressure cooker bombs >> turned it back over to the city. >> people in a matter of five days and sweeping in. >> a moment of silence at 2:50 p.m., remembering the victims one week after bombs killed three people and wounded more than 170. >> okay. let's get detail news on the charges against tsarnaev and what he is telling authorities. erin mcpike is live in boston with more on that. erin, what have investigators learned from the suspect? >> isha, right now we know that dzhokhar tsarnaev can't speak very well. but from what he has indicated to the authorities, he says -- for what he has indicated, no foreign terrorist groups were involved in the bombing. the brothers were radicalized online. they say it's not from online communications, but rather from watc

i'm jonathan mann. >> and i'm isha sesay. dzhokhar tsarnaev is talking to authorities. >> and it's been eight years since this video has become the first one ever uploaded to youtube. >> let's start with the latest developments. we're learning much more about the bombings last week. >> the information is coming from the sole surviving suspect in the explosion. from the hospital bed joe hadzh tsarnaev is communicating. >> he's saying his older brother, tamerlan, was the driving force. >> he said no international terror groups were involved. dzhokhar indicated that he and his brother acted alone. he knew of no more bombs were hidden. we also have more pictures and surveillance photos of him leaving a bank machine in watertown. they allegedly car jacked a driver. a few hours later a gun fight erupted and dzhokhar's older brother, tamerlan was killed. later dzhokhar tsarnaev was captured. let's go to erin mcpike at the boston hospital where dzhokhar is being treated. he's under restraint, handcuffed to his bed. i gather that hosp