>> let's bring in chad sweet, former chief of staff with the department of homeland security also a former cia officer, co-founder and ceo of the chertoff group. also tom fuentes, juliette kayyem here. a lot of information here first and foremost the brothers believed to be from chechnya. let's start with that. >> couple points. one is, if they're in, fact, students at bunker hill college, there's the student immigration visa data base which will follow things like we'll know exactly their bigraphic information. there will have been fingerpr t fingerprints provided for the application. which will not only allow us to do forensics on the post-blast investigation but tie it from an evidentiary point of view to prosecute them. it will also be interesting to see as suggested before, we'll be able to zero in behind the scenes right now, all the focus is on tightening the noose