is extensive. we are joined by a forker former special agent at the a.t.f. so bernard, going in, bowers apparently tweeted that he's going to do just that. he said screw the optics going in, just before the shooting. he's got full line in the social media, full of anti-semetic rantings. what is the line, where is the line from this type of expressions to criminality to this horrific mass killing? >> this is historic hate in the united states. it's historic state from the 18th century forward and it goes on. it's very reminiscent of activities that have happened in the last five years in the united states. these type of shooters, particularly the anti-semetic often telegraph their punches with their rhetoric. say preinternet it was postings or tennets at these meetings. we have to pay attention to