that ability, when this happened, as ed davis said, to call the fbi, to call the state police, have everybody working with the public, trusting what we were doing, including the closing of boston friday, that work is going to have to continue, and i think it's one of the reasons that boston was so successful in mitigating the damage here, in coming together as a community, in solving this and bringing these men into apprehension, the one who survived. but that work isn't done. it's going to continue. >> all right. massachusetts attorney general martha coakley. thank you so much for being with us this morning. i know you've been going to the memorials and services and you will continue to do so. >> it's a tough week. this is a grieving week for everybody. >> i appreciate it. meantime, investigators are examining the activities of tamerlan tsarnaev, including a trip that he took last year to russia. he was on the fbi's radar for a short time in 2011 because of concerns about possible islamic extremism. so the question is, did the agency simply miss the warning signs here? joe johns is in washington with that part of the story. good morning, joe. >> good morning, john.