pleaded guilty and agreed to cooperate. it's so surreal, paul butler, to go from reporting on the former chairman of his campaign to reporting on the former the forl security adviser for the united states of america under donald trump as cooperating witnesses in the mueller probe into russian collusion. >> yeah, so part of this, again, we've always thought of this as a pyramid prosecution. you start at the bottom and go up. it's always been interesting that the people on the bottom are pretty high ranked like michael flynn and like the former chairman of the campaign. but, look, all this means is that michael flynn has done what he was supposed to do for special counsel mueller. mueller has preserved that testimony in the grand jury and now he kind of puts it on ice. michael flynn was a convicted liar. he was never going to be a witness in a criminal case. and mueller still has a whole lot to do. he has to debrief and preserve