It seems to me that if the Feds were confident about their murder-for-hire claim, they would have charged Ulbricht accordingly. That they chose not to do so indicates they were less than confident, and we should draw our conclusions accordingly.
For all I know he may well have been involved in murder for hire; I haven't paid close enough attention to the case to have an opinion. But I've followed too many hacker cases to accept unrebutted DOJ allegations as gospel truth.
Capone went away for tax evasion, right?