Mr. Stone boasted repeatedly in 2016 that he was in touch with WikiLeaks and had inside information about its plans to release emails that would undermine Mrs. Clinton’s campaign. Later, when the special counsel and congressional committees began investigating Russian interference in the election, he said his claims were mere puffery.
How much if anything Mr. Stone knew about what WikiLeaks had in store for the Clinton campaign has been a mystery since Aug. 21, 2016, when Mr. Stone wrote on Twitter, “Trust me, it will soon the Podesta’s time in the barrel.”
That prediction seemed remarkably prescient because about six weeks later, WikiLeaks began releasing 50,000 emails that Russian agents had stolen from the computer of John D. Podesta, Mrs. Clinton’s campaign chairman.
Mr. Stone told the House committee that his Twitter message was based on research from a friend about the business dealings of Mr. Podesta and his brother in Ukraine. The friend, Jerome Corsi, initially backed up Mr. Stone’s account. But in interviews with investigators, he said that was merely a “cover story” that he and Mr. Stone devised.
Mr. Zelinsky, the prosecutor, told a predominantly female jury on Wednesday that Mr. Corsi was one of two intermediaries whom Mr. Stone deployed in his efforts to get in touch with Mr. Assange. The other was Mr. Credico, a New York radio host, whom prosecutors said Mr. Stone pressured to either lie or stonewall the House committee.
Mr. Stone also told Mr. Credico not to cooperate with Mr. Mueller’s investigation, said Mr. Zelinsky, who worked on the inquiry. In a January 2018 text message, Mr. Stone described the special counsel’s investigation to Mr. Credico as a “waste of your time.”
Mr. Zelinsky said Mr. Credico would testify but suggested that he might seem unreliable. “If you were looking for someone to pin something on, Randy Credico is a pretty good person to pick,” he said. But he said that to an “amazing” degree, most of the evidence of the case was contained in documents.
The defense was expected to make its opening statement on Wednesday afternoon. The charges against Mr. Stone carry a maximum penalty of 20 years.
Zach Montague contributed reporting.