Silk Road prosecutors rest their case, cite 'mountain' of digital evidence

"The evidence is overwhelming that Ross Ulbricht started Silk Road, and kept it running until his arrest," the lead prosecutor, US Justice Department Attorney Serrin Turner, told the jury. He reminded them of the "mountain of evidence" presented by prosecutors that included Ulbricht's Gmail and Facebook accounts, as well as thousands of pages of chat logs and a journal found on the laptop that Ulbricht was using during the time of his arrest.

Federal prosecutors had only one witness who directly tied Ulbricht to Silk Road, Richard Bates, a friend who helped Ulbricht during early days of the site with some technical details. So the case was made largely on digital evidence. Turner carefully walked the jury through multiple examples where Silk Road administrative records correlated closely with digital evidence tied to Ulbricht, and the computer he was using during his arrest.

"There are no little elves who put all this evidence on his computer. Use your common sense, ladies and gentlemen," Turner implored the jury.

Prosecutors must convince the jury that Ulbricht had a hand in the operation of the site through at least a portion of its lifetime -- January 2011 until October 2013 -- a challenging task given that the site was managed largely through a pseudo-anonymous administrative account, under the name Dread Pirate Roberts.

The prosecution's case seeks to prove that Ulbricht operated Silk Road using that account. Ulbricht is charged with narcotics conspiracy, engaging in a continuing criminal enterprise, conspiracy to commit computer hacking and money laundering. The narcotics and criminal enterprise charges carry maximum penalties of life in prison. Ulbricht has pleaded not guilty to all charges.

Ulbricht's defense lawyer, Joshua Dratel, argues that Ulbricht handed off the site to other operators shortly after he started it in 2011, and that he rejoined immediately prior to his arrest, lured back in by the new operators to serve as a fall guy.

Turner pointed that none of digital evidence, collected both from Ulbricht's laptop and the Silk Road servers, indicates that there ever was a handoff between Ulbricht and another party. Moreover, the laptop Ulbricht was using during his arrest contained a rich history -- as found in server logs, bookkeeping spreadsheets and a journal -- of how Silk Road came to be.

Turner reiterated those points where the Silk Road records closely correlated with Ulbricht's personal records. No single piece of evidence conclusively proves Ulbricht was Dread Pirate Roberts, but if added up, the collective evidence offers strong proof that the two were one and the same, Turner argued.

For instance, chat logs showed Dread Pirate Roberts boasting of a romantic date on the same day Ulbricht's personal email records from OKCupid show an interaction with a woman he went on a date with. On multiple occasions Ulbricht's email and Facebook account showed evidence of him going on trips, such as to Thailand or on a family boating expedition, at the exact times Dread Pirate Roberts told his fellow administrators that he would be offline taking vacations.

At one point Ulbricht e-mailed a friend a picture of a lizard that he kept as his laptop's desktop image. However, the desktop image, presumably captured by a utility on the laptop, also captured the second screen Ulbricht was supposedly using at the time, which showed two chat windows open with ongoing conversations with two known Silk Road administrator accounts.

Chat logs also revealed discussions Dread Pirate Roberts had with fellow Silk Road operators about the possibility of picking up a second citizenship in the Caribbean island of Dominica. On Ulbricht's laptop was a form for applying for Dominica citizenship.

Dratel will present the defense's closing arguments later Tuesday. U.S. District Judge Katherine Forrest is overseeing the case

Joab Jackson covers enterprise software and general technology breaking news for The IDG News Service. Follow Joab on Twitter at @Joab_Jackson. Joab's e-mail address is Joab_Jackson@idg.com