Russian analyst Igor Danchenko arrives at the Albert V. Bryan U.S. Courthouse before being arraigned on November 10, 2021 in Alexandria, Virginia.
Alexandria, Virginia CNN  — 

The jury in the trial of Trump-Russia dossier source Igor Danchenko began deliberations Monday and will decide if he lied to the FBI about where he got his information.

The case was brought by special counsel John Durham, who has a lot riding on the outcome. After more than three years looking for misconduct in the FBI’s Trump-Russia probe, Durham has only secured one conviction. The Danchenko case is the final expected trial before Durham wraps up his investigation.

Jurors are now deliberating at the federal courthouse in Alexandria, Virginia. Danchenko was initially charged with five counts of lying to the FBI, but a judge threw out one of the charges Friday, in a major blow to Durham.

Danchenko pleaded not guilty to all charges and says he told the truth to the FBI.

Danchenko, a Russian expat and think-tank analyst, was the primary source of material for the infamous Trump-Russia dossier. The collection of unverified and salacious allegations was compiled by retired British spy Christopher Steele, whose work was indirectly funded by Hillary Clinton’s 2016 campaign. The largely discredited memos accused Donald Trump of collaborating with the Kremlin to win the election.

A guilty verdict would give a major boost to Durham. But an acquittal would be an embarrassing defeat for the special counsel, whose only other trial, against a Clinton campaign attorney, ended in a swift acquittal in May from a federal jury in Washington, DC.

A lawyer for Danchenko blasted Durham during closing arguments on Monday, accusing prosecutors of misleading the jury and ignoring key evidence while on a “mission to prove him a liar.”

The case against Danchenko revolves around whether he lied to the FBI in 2017 about his sourcing for the so-called Steele dossier. During closing arguments, Danchenko lawyer Stuart Sears said prosecutors brazenly cast aside information that “doesn’t support their narrative that he’s a liar.” Sears pointed out how Durham turned on his own witnesses after they provided evidence that helped the defense.

“The special counsel attacked them mercilessly,” Sears said. “They attacked the credibility of the very witnesses they called in here, because they didn’t say what they wanted them to say.”

Sears added: “The government’s own evidence in this case proves that the defendant is not guilty.”

Durham’s team urged jurors to convict Danchenko on Monday, telling them to “look at his own words” in emails from 2016 that they believe prove that he later misled the FBI about his ties to a possible dossier source.

“You didn’t check your common sense at the courthouse door,” prosecutor Michael Keilty said. “You need to use it.”

Keilty said Danchenko gave a “shifting story” to the FBI agents who interviewed him in 2017, while they were trying to corroborate the explosive allegations in the dossier that Trump’s campaign was colluding with the Russian government to win the presidency.

“The FBI surveilled a US citizen for nearly a year based on those lies,” Keilty said, referring to the wiretaps of former Trump campaign adviser Carter Page. The FBI affidavits used to secure those surveillance warrants included material that came from the Trump-Russia dossier.

Danchenko’s lawyer also blasted the Trump-era Justice Department for “exposing” him as an FBI informant and for launching the probe that led to his prosecution.

“He was trying to help the FBI, and now they’re indicting him for it,” Sears said.

As a paid informant, Danchenko significantly assisted multiple FBI probes between 2017 and 2020. But the FBI was forced to cut ties with Danchenko in late 2020, after the Justice Department indirectly outed him as a dossier source.

“He deserved more than to be exposed because a bunch of politicians put politics over national security,” Sears said.

Danchenko’s handler, FBI agent Kevin Helson, testified last week that Danchenko’s outing harmed US national security. Internet sleuths identified Danchenko shortly after then-Attorney General Bill Barr publicly released Helson’s notes of his Danchenko interviews. Barr took that action after facing pressure from Trump and Republican lawmakers to release more internal FBI files about the Russia investigation.

Durham personally defended the legitimacy of his investigation Monday during closing arguments, saying the FBI’s Trump-Russia probe was so flawed that it warranted a second look from his team.

Durham also told jurors that they shouldn’t “feel bad for the FBI agents” because “the FBI failed here on a number of occasions.”

This story has been updated with additional details.