unexploded devicesment . we're getting information that some of the devices contain ball bearings. other contain nails, zippers and blades. but not only that, we are also told that some of the other devices did not contain shrapnel but are being described as crude and relatively small in size. as you indicated earlier, the fbi is leading this investigation. >> this will be a combined federal, state and local effort. it will be an on going investigation. it is a criminal investigation that is -- has the potential -- is a potential terrorist investigation. >> and another indication of them leaving no stone unturned, they even spent hours in an apartment building in raveer, massachusetts, five miles north of boston, where they were checking out an apartment in this building. as far as we know, they did not leave with any suspects in hand.