prosecutors appears to increase the legal peril facing the congressman. joining us now is joyce vance, a professor at the university of alabama school of law and an msnbc legal contributor. joyce, good to see you. joyce, explain to us how this all works. greenberg was facing 33 or 34 charges, and he cut some deal in which he pleads guilty to 6 of them, probably is going to do some time, but they don t tell him how much time he s going to do until the end of this thing because he s got to give up a lot of information. and it seems they re now starting to connect dots. you ve just given a great explanation of how federal cooperation and sentencing works. essentially a defendant who wants to cooperate has to give him or herself up to the good graces of federal prosecutors, and any credit for cooperation is in their sole discretion. they have to act in good faith, but it s up to them to determine whether or not the cooperation has been successful. so greenberg, who is now looking