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...
The prosecution memo does not rebut this argument, it rebuts instead the clearly different but related argument that the murder-for-hire scheme was uncharged conduct which could therefore not be considered in sentencing. It was -- as they correctly point out -- charged, as it was one of the overt acts specifically laid out in the Count One narcotics trafficking conspiracy charge.
It is nevertheless inaccurate to say he was convicted of hiring a hitman, since a conspiracy conviction requires (as far as overt acts go) only a finding that the defendant committed at least one overt act in furtherance of the conspiracy, there were several overt acts charged in that count, and the verdict form did not direct the jury to return separate findings of fact on each charged overt act.