cnbc producer justin solomon, a boston native, is there and has told us that what he's been seeing ispartment arriving on the sight, agents going into the building with dogs, the building has been evacuated, because of what is apparently an unrelated bomb threat and much of the media had been drawn there, based on an inaccurate report that there was a suspect or suspects in custody that were going to be brought to the courthouse. the media throng has been pushed back further and further, according to justin solomon, and we are awaiting what that is all about. here's what we know, and what has been going on today. around mid-morning, we saw heightened activity on boylston street, the scene of the crime, a lot of evidence technicians swarming the scene, from the fbi, the atf. they were going through, everything from port-a-potties, picking up scraps, things on the ground, actually going up on the roofs to see whatever other scraps of evidence they could come up with, as you see in the pictures that we shot earlier today. they also now, i'm being told, the search for evidence was quite f