>> the investigation begins in spring 2017. mueller assembles a team of the some of the highest profile and seasoned investigators. >> one thing he's always been able to surround himself with people that are very good. and that's probably one of the skills he has that allowed him to succeed. >> the way to best understand mueller's investigation is look at it as buckets. there' russia bucket an obstruction bucket and the finance bucket. the bucket we know the most about is obstruction. questions about what the president has done since he came into office. why did he fire james comey. why did he ask for him to end want flynn investigation. and demanded so much loyalty of the folks running the investigation. >> within indictments handed up and guilty pleas from multiple trump soeshlts the probe shows no sign of winding down. >> has there ever been a new presidency where four members of the presidential campaign ended up charged with felonies before