Mark Karpeles

Mark Karpeles, owner of the Mt. Gox bitcoin exchange, became a focus of the defense's theory that someone other than Ulbricht operated Silk Road as Dread Pirate Roberts (DPR). During Joshua Dratel's cross-examination, HSI agent Jared Der-Yeghiayan described investigating Karpeles before Ulbricht came to his attention in September 2013. He confirmed that silkroadmarket.org used a hosting company owned by Karpeles and described matching MediaWiki version numbers on websites he compared. He also acknowledged that he had not examined Karpeles' computers, phone, or overseas servers. The court instructed jurors that unverified online claims about Karpeles' programming expertise were not proof of that expertise. On redirect, Der-Yeghiayan explained that MediaWiki was freely downloadable; later testimony clarified that the associated hosting-support inbox served multiple customers.

Judge Katherine B. Forrest allowed admissible factual evidence supporting an alternative-operator theory but barred the agent's beliefs, suspicions, and legal conclusions about culpability. She also excluded an alleged offer through Karpeles' lawyers to identify DPR in exchange for leniency. Over the defense's waiver objection, she directed counsel to proceed as though identified earlier testimony would be struck, while explaining that other factual evidence concerning Karpeles would remain. Dratel returned to Karpeles' hosting connections and investigative gaps in closing argument, and prosecutor Timothy Howard challenged the suggested connection in rebuttal. Those competing arguments did not establish that Karpeles operated as DPR.