agencies can quickly identify is this potentially homegrown, is it potentially offshore inspired? they'll certainly be checking any threats that have been recently made relative to this event. the police commissioner of boston, ed davis, earlier in the press conference indicated they had had no previous threats made against the event, so that was based on his understanding of what's going on. >> what do you expect in terms of people taking responsibility for this attack? >> that's going to complicate it in the early stages because they'll probably be coming out of the woodwork to claim credit and that's the usual circumstance after one of these incidents. and, again, that's where the coordination between the various intelligence services, state, local, and national, will be critical to actually what type of chatter has there been that they've been monitoring in recent days? was there an increase in chatter