Ross Ulbricht, 30, is charged with conspiracy, money laundering, and narcotics trafficking for his alleged role in building and running Silk Road until he was arrested in October 2013.

Jared Der-Yeghiayan, a Department of Homeland Security special agent, told jurors that he began investigating Silk Road when he noticed that many of the drug shipments coming through Chicago's O'Hare International Airport — where he worked at the time — matched up with photos, descriptions, and "shipped from" location of the drugs advertised on Silk Road's website.

Exploring further, Der-Yeghiayan and his team at Homeland Security Investigations set up an undercover Silk Road account under the username "dripsofacid." The team transferred $7,000 to the bitcoin exchange Mt. Gox Co. in exchange for 27.27 bitcoins on April 5, 2013, he told jurors. The team used 24 of them — approximately $5,500 — to purchase 1,000 200-milligram Ecstasy pills from user "SuperTrips" that were to ship from Germany, according to Der-Yeghiayan.