reporter: when you hear about this, your initial reaction when you hear robel is arrested? it doesn t make sense. robel doesn t have anything to do with this so i don t see why he has been arrested. reporter: do you think he would lie to cover for the tsarnaev brother? no. i don t think so. reporter: don t think he would. no. reporter: not that kind. what about you? any political agenda that you ever this was all about we hear, right, muslim and u.s. things, so what robel is a christian. doesn t have any anti-american thing about him. neither did dzhokhar. reporter: never heard anything from dzhokhar along those lines. never. reporter: stunning new twist in the boston case, coverup charges against three friends of the surviving bombing suspect including hiding or destroying evidence, making false statements to investigators. joining us now our cnn national security analyst. the former fbi assistant dr. tom fuentes and the former homeland security assistant sec