President Trump’s friend and political adviser Roger Stone is set to go on trial Tuesday in a proceeding that could reveal just how close Trump world got to the Russian interference in the 2016 election.

Jury selection is scheduled to commence following months of unusual public silence from Stone, who has been gagged by the judge in his case following a flap this year over his posts on social media.

Stone pleaded not guilty in January after a grand jury in Washington, D.C., returned an indictment with one count of obstructing a proceeding, five counts of making false statements to Congress and one count of witness tampering — because prosecutors allege that he tried to persuade another witness to lie to Congress too.

Neither Stone nor any other Trump insider has been charged with colluding with Russia’s interference in the 2016 election; former Justice Department special counsel Robert Mueller concluded that there wasn’t enough evidence to bring a case of conspiracy.

Stone says he has done nothing wrong.

He joined Trump and others in blaming “biased” officials within the “deep state” for abusing their powers.

One of the targets for that blame earlier this year was the judge in his case, Amy Berman Jackson, whom Stone’s Instagram account then made the subject of criticism.

Jackson summoned Stone to court for a warning, and then, after what she determined was too little care by him or those with access to his social media accounts, Jackson tightened the gag in July.

Chain of contacts

Stone and some of his associates may have been links in a chain that connected Trump in New York City with WikiLeaks founder Julian Assange in London, who at the time had confined himself in the Ecuadorian Embassy there.

Assange, in turn, was in contact with Russia’s military intelligence agency, the GRU, which had stolen a trove of embarrassing material from political targets in the United States.

WikiLeaks released many of those emails and other documents with disruptive effects on political life in the U.S. — and enjoyed public encouragement by Trump and his campaign.

What Mueller’s investigation revealed was how much Trump and aides worked to get more.

The campaign built into its plans the expectation that there would be more damaging revelations about Hillary Clinton, and Trump’s campaign bosses also sought contact with some people connected with the interference over the course of the election season.

Charging documents in Stone’s case describe a message from one of Stone’s contacts depicting the person in a photo taken outside the Ecuadorian Embassy — implying that he’d visited Assange — and other messages in which Stone and associates discuss the prospect of more “dumps” from WikiLeaks.

WikiLeaks released a trove of emails by Clinton’s campaign chairman in October 2016 on the same day that a video recording appeared of Trump boasting in crude terms about his power over women.

Investigators never established publicly whether there was any connection between these two events.

Although Trump campaign bosses praised Stone at the time the WikiLeaks release took place, he has since argued that he actually took no action and simply let his interlocutors believe he was stage-managing events that were playing out on their own.

Also, at least one of Stone’s associates is described in court documents as saying that he too actually had no back channel to Assange.

The charges

Prosecutors allege that Stone lied about much of this to Congress.

He told lawmakers he didn’t have any emails, text messages or other documents related to the matter. Prosecutors also charge that Stone lied about his communications with others, including the associates whom he told to be in contact with Assange.

In the case of one other potential witness, Stone is described in charging documents as urging him to copy a character from The Godfather Part II, Frank Pentangeli, and pretend, when he appears for a hearing before members of Congress, not to know what he really knows.

What’s less clear is how much Stone talked about WikiLeaks with Trump and campaign aides.

The section of Volume I of Mueller’s report that describes Trump’s enthusiasm about getting Clinton’s emails, pages 52 through 57, are heavily redacted, but they suggest that Trump and campaign chairman Paul Manafort were personally involved.

The explanation given for the redactions was “harm to ongoing matter,” presumably the prosecution of Stone. If the U.S. Attorney’s Office for the District of Columbia reveals those previously redacted details in court to establish facts that it says prove that Stone lied about, key areas of the story could be confirmed for the first time.

For example, did Stone or his associates truly communicate with Assange, and if so, how? Was the nature of that link purely about the stolen political material, or was there more?

A section in Stone’s indictment describes how one putative intermediary told Stone that Trump’s campaign should begin drawing attention to Clinton’s supposed ill health, as it later did. What was the origin of that messaging strategy, and were there other offers like it?

Updated at 3:56 p.m. ET

Ousted former U.S. Ambassador to Ukraine Marie Yovanovitch told congressional investigators that she was warned to “watch her back” by a senior Ukrainian official, according to the newly released transcript of Yovanovitch’s closed-door deposition before Congress.

The Ukrainian official told her that Rudy Giuliani’s associates, Lev Parnas and Igor Fruman, who have since been arrested on an unrelated charge, wanted a different ambassador in the post. Why?

“I guess for — because they wanted to have business dealings in Ukraine or additional business dealings,” Yovanovitch told House Intelligence Committee members, which include Republicans. “I didn’t understand that, because nobody at the embassy had ever met those two individuals. And, you know, one of the biggest jobs of an American ambassador of the U.S. Embassy is to promote U.S. business. So, of course, if legitimate business comes to us, you know, that’s what we do — we promote U.S. business.”

The Oct. 11 testimony is among the first transcripts of closed-door depositions from individuals at the center of the Ukraine affair, which has landed President Trump in an impeachment inquiry.

The transcripts, released Monday, are of the separate, hours-long depositions of Yovanovitch and Michael McKinley, a former senior adviser to Secretary of State Mike Pompeo. McKinley, a career foreign service officer, said Yovanovitch’s treatment “raised alarm bells” and “had a very serious effect on morale” at the State Department, and he described “bullying tactics.”

“I’m just going to state it clearly,” McKinley told Congress. “As a foreign service officer, to see the impugning of somebody I know to be a serious, committed colleague in the manner that it was done raised alarm bells for me.”

Yovanovitch, who has decades of diplomatic experience, was recalled as ambassador in May, and on his July phone call with Ukrainian President Volodymyr Zelenskiy, Trump referred to her as “the woman” and “bad news.”

The Ukrainian official who gave Yovanovitch the heads-up of Parnas’, Fruman’s and Giuliani’s involvement was Arsen Avakov, Ukraine’s minister of internal affairs. He told Yovanovitch that he had become aware of Giuliani’s pressure campaign to get Ukraine to investigate conspiracy theories about the 2016 election and former Vice President Joe Biden and his son, Hunter.

On Trump’s call with Zelenskiy, the U.S. president asked for the same investigations to be undertaken as “a favor,” according to a White House-released account of the call. Trump’s request came right after Zelenskiy asked to buy more U.S. weapons. The U.S. also was withholding military funding that had already been allocated by Congress. Trump encouraged Zelenskiy to work on the investigations with Giuliani — the president’s personal lawyer — and Attorney General William Barr. (There’s no indication that Barr played any role in the affair.)

Hunter Biden served on the board of Burisma, a Ukrainian energy company, while his father was vice president and handling issues related to Ukraine. There is no evidence of wrongdoing from either Biden, but Trump and Giuliani have used the fact of Hunter Biden’s serving on the board as a way to politically deflect to the Bidens.

For most of 2019, Joe Biden led national polls of the Democratic primary and led Trump in 2020 general election polling, setting him up as a principal potential contender to take on the incumbent president.

“Did the issue come up in that conversation or others about the Giuliani and his associates’ interest in the Bidens and Burisma?” asked a Democratic staff counsel of Yovanovitch in the closed-door deposition.

“Yeah,” Yovanovitch said. “I mean, looking backwards to what happened in the past, with a view to finding things that could be possibly damaging to a presidential run.”

Asking for clarification, House Intelligence Committee Chairman Adam Schiff of California interjected: “By Joe Biden?”

“Uh-huh,” Yovanovitch replied.

Yovanovitch also noted that she reported her conversation with Avakov back to the State Department, so there is a record.

“Everybody is sort of shocked,” Yovanovitch said of the State Department’s reaction.

The release of the transcripts is one of the first steps in the new public phase of the impeachment inquiry. Opening statements had previously been released, but these transcripts, which are hundreds of pages long, include full questions and answers with some sensitive items redacted.

Schiff promised to release more transcripts Tuesday — from former special envoy to Ukraine Kurt Volker and Ambassador to the EU Gordon Sondland. Sondland was a major Trump donor, and witnesses have contradicted parts of Sondland’s testimony.

Yovanovitch detailed a campaign to oust her from her post, and when she spoke to Sondland about the campaign against her, he told her that she should tweet her praise for Trump.

“You need to, you know, tweet out there that you support the president and that all these are lies and everything else,” Yovanovitch said, paraphrasing what Sondland told her. “And, you know, so, you know, I mean, obviously, that was advice. It was advice that I did not see how I could implement in my role as an ambassador and as a foreign service officer.”

In the other released deposition, McKinley noted concerns about “bullying tactics” at the State Department after complaints were lodged about getting information to Congress in a timely manner. And he said he was “absolutely appalled” that the State Department was not going to provide legal financial support for people who had to go and testify before Congress.

Four administration officials defied congressional subpoenas and chose not to testify in closed-door depositions Monday despite being scheduled to do so. Schiff said those four will help build a case for an article of impeachment that includes obstruction of Congress’ constitutionally mandated duties.

Schiff called all four of them “firsthand witnesses” to serious allegations of misconduct.

“We may infer that their testimony would be further incriminating for the president,” Schiff argued, adding that the administration’s strategy of not cooperating amounts to “delay, deny, obstruct.”

Schiff also noted that transcripts from Yovanovitch and McKinley detailed the “back channel” efforts by Giuliani, which he said included “a vicious smear campaign” to remove Yovanovitch.

He declined to comment on whom the committee planned to ask to appear in public hearings.

NPR’s Deirdre Walsh contributed to this report.