edit: this is something that vice news [0] reported that is apparently wrong.
> But despite these setbacks, Ulbricht was ultimately convicted in February on a raft of charges, including drug trafficking, computer hacking, money laundering, and hiring assassins to take out members of Silk Road.
[0]: https://news.vice.com/article/ross-ulbricht-convicted-master...
Ulbricht's argument to the effect that he wasn't properly charged with the murder-for-hire scheme was addressed in detail by the court:
https://s3.amazonaws.com/s3.documentcloud.org/documents/1391...
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.