Then why was he not prosecuted for that? There wasn't even enough evidence to bring that to the trial.
There's really very little reason to doubt he did it, either.
The prosecutor "addressed the jury and stated that none of the six contracted murders-for-hire occurred." These charges were dismissed with prejudice.
https://en.wikipedia.org/wiki/Ross_Ulbricht#Silk_Road,_arres...
That doesn't let Ross off the hook for attempting to make them occur.