and j.m. berger. he has written extensively about political violence. latest book, "extremism" was recently published by mit press. he's also a research fellow at vox-pol, a european unionad ic initiative to study online extremism. we welcome both of you to the program. mary mccord, to you first, what's your reaction about what we know so far about this man, the susct >> well, it does seem like it was extremely good and fast work by the fib and other local and state law enforcement that assisted. ey got lucky by the fact that the suspect left a furykprint on one of the packages and is sobody known to law enforcement for whom his fingerprint was in the database. so congratulations, of cllrse, to the incredible law enforcement for solving tis so rapidly. but the investigation will go to make sure that there are no ombsrs involved, no other b out there already in the stream of mail or in delivery services, and, you know, at no one else that this suspect is working with. >> woodruff: j.m. berger, it is the case that this investigation continues. with we are