One point that has always stood out: The Feds knew Rocco was part of Michael's Family--he was way up there on the chart shown at the Senate hearing. Dead or alive, they would have had a direct link between Rocco, Roth and Michael.
Which raises the question: Why send Rocco to personally perform the hit on Roth, in public view, for all the world to see? Maybe a bit of directorial license comes into play at this point, but I was under the impression that professional hit men were generally hired for this kind of duty, the more obscure and anonymous the better, specifically so that they would
not reveal a connection to the person or family who hired them - if they should be so unfortunate as to get killed or captured while in the act.