constructed. what do you know? >> the belief number one is that both of the brothers had a remote device to blow up each of the two bombs. now, in terms of the ingredients, we know that they're still analyzing a lot of this information, but they do know that one of the pipe bombs that was used in the shootout in watertown, those improvised devices were in fact constructed from elbow pipes. now, elbow pipes, that is one instruction method, rather, that comes up from time to time in "insfi "inspire" magazine which is something that has been used and promoted by al qaeda to give information about how to make a bomb. so that bit of information also is an important part of this alleged plot investigation. >> what about the suspect's level of cooperation? there has been a lot of talk from different people about how he may have stopped giving investigators information once he was mirandized.