but they do know that one of the pipe bombs that was used in that -- the shootout in watertown, those imp ro vised devices, weren't constructed from elbow pipes. now, elbow pipes, that is one instruction method, rather, that comes up from time-to-time in inspii "inspire" magazine that is used and promoted by al-qaida to use and how to make a bomb. so that information is also an important part of this investigation. >> what about the suspects level of cooperation? there's been a lot of talk from a lot of different people about how he may have stopped giving investigators information once he was mir an diezed. is that accurate? is that true? >> well, sources are telling me that the investigators and one official used this term, were very thorough. that they got a lot of information from this young man