washington u.s. district court judge order special counsel robert mueller tuesday turn potential evidence could material sentence president donald trump former national security adviser michael flynn flynn plead guilty early month lie federal bureau investigation interview mueller probe russian meddle 2016 presidential election whether trump campaign collude russia flynn agree cooperate mueller investigation moscow deny interfere election trump deny collusion u.s. district judge emmet sullivan tell government file turn exculpatory evidence know brady material could potentially help flynn defense information material either defendant guilt punishment order judge consider routine government law require turn information defense exist sentence date set status report ahead sentence due feb 1. u.s. judge order special counsel turn evidence michael flynn