tsarnaev brothers got any helper happens from any militant inside dagestan. cnn's miguel marquez has the latest on this angle from the streets of boston. good morning, miguel. >> reporter: good morning, john. lots of details starting to come to light in this investigation. i want to take you back to the place where this began though, the finish line of the boston marathon. and what's incredible here is just how close the first bombing was. i don't think you get a sense of that from the video we all watched together. this little spot here on boylston street now, hallowed ground. investigators tell cnn and other news agencies at least one of the homemade bombs was triggered by remote control, possibly a crucial clue. were the devices based on a blueprint in al qaeda's english language magazine "inspire" or similar to ones built in camps by abu dujan. whether he or tamerlan tsarnaev