>> reporter: you have the physical evidence and the digital evidence that was removed. when it comes to the physical items, you have, for example, several different bomb-making materials as to what they refer to it. you have the components of a small bomb making factory and files and documents, a hard drive, too smashed up, heavily damaged phones recovered nearby. investigators hope that could provide them with a key clue or at least several key clues that they need to try to finally establish that connection. we found out yesterday this case will be treated as a terrorism investigation, which...