Julian Assange not only knew that a murdered Democratic National Committee staffer wasn’t his source for thousands of hacked party emails, he was in active contact with his real sources in Russia’s GRU months after Seth Rich’s death. At the same time he was publicly working to shift blame onto the slain staffer “to obscure the source of the materials he was releasing,” Special Counsel Robert Mueller asserts in his final report on Russia’s role in the 2016 presidential election.

“After the U.S. intelligence community publicly announced its assessment that Russia was behind the hacking operation, Assange continued to deny that the Clinton materials released by WikiLeaks had come from Russian hacking,” the report reads. “According to media reports, Assange told a U.S. congressman that the DNC hack was an ‘inside job,’ and purported to have ‘physical proof’ that Russians did not give materials to Assange.”

Thursday’s long-anticipated release adds new details about Assange’s interactions with the officers in Russia’s Main Intelligence Directorate. Still, it leaves one question unanswered: Why was Assange so determined to exonerate the Russian intelligence agents who gave him the material?

As laid out by Mueller, Assange’s involvement in Russia’s election interference began with a June 14, 2016 direct message to WikiLeaks’ Twitter account from “DC Leaks,” one of the false fronts created by the Russians to launder their hacked material.

“You announced your organization was preparing to publish more Hillary's emails,” the message read, according to Mueller’s report. “We are ready to support you. We have some sensitive information too, in particular, her financial documents. Let's do it together. What do you think about publishing our info at the same moment? Thank you.”

A week later, WikiLeaks reached out to a second GRU persona, Guccifer 2.0, and pitched WikiLeaks as the best outlet for the hacked material. On July 14, 2016, GRU officers used a Guccifer 2.0 email address to send WikiLeaks an encrypted one-gigabyte file named “wk dnc link I .txt.gpg.” Assange confirmed receipt, and on July 22 he published 20,000 DNC emails stolen during the GRU’s breach.

By then, it was no secret where the documents came from. The computer security firm CrowdStrike had already published its technical report on the DNC breach, which laid out a trail leading directly to Moscow and the GRU. Analysts at ThreatConnect independently presented evidence that Guccifer 2.0 and DC Leaks were fictional creations of that agency.

But rather than refuse to comment on his sources, as he’s done in other cases, Assange used his platform to deny that he got the material from Russians, and make statements at an alternative theory. On August 9, 2016, WikiLeaks’ Twitter feed announced a $20,000 reward for “information leading to conviction for the murder of DNC staffer Seth Rich.”

For some, the cryptic tweet was their first introduction to a grim and fantastical conspiracy theory rooted in a real-life tragedy that occurred the early morning of July 10, 2016 on a Washington DC sidewalk.

Rich was a 27-year-old DNC staffer when he was gunned down in what police have described as a robbery gone wrong. The unsolved murder timed shortly before Assange’s DNC leaks spoke volumes to inhabitants of the far right wing fringe, where it’s long been an article of faith that Hillary Clinton has her enemies killed.

Assange fanned the flames even higher on August 25, 2016, when he was asked in a television interview, "Why are you so interested in Seth Rich's killer?"

"We're very interested in anything that might be a threat to alleged Wikileaks sources,” Assange answered. “If there's someone who's potentially connected to our publication, and that person has been murdered in suspicious circumstances, it doesn't necessarily mean that the two are connected. But it is a very serious matter .. that type of allegation is very serious, as it's taken very seriously by us."

Assange never came out and said it, but his “ statements about Rich implied falsely that he had been the source of the stolen DNC emails,” Mueller notes.

With Assange behind it, the Seth Rich hoax moved into the almost-mainstream, spawning a quickly-retracted report on Fox News, and a series of “investigations” by Assange ally Sean Hannity. It also wreaked havoc in the lives of Rich’s surviving family, particularly his anguished parents who later begged perpetrators of the charade “to give us peace, and to give law enforcement the time and space to do the investigation they need to solve our son's murder.”

Even as he was ruthlessly framing Rich to protect himself, the GRU, or both, Assange was privately communicating with his real sources to arrange the transfer of the second election leak, material the GRU stole from John Podesta’s Gmail account.

The Mueller report quotes from cryptic emails and messages exchanged between WikiLeaks and the GRU accounts in September 2016, and based on metadata, Mueller suspects the transfer occurred on September 19. But the actual transmittal of the massive Podesta haul evidently took place in a channel that Mueller couldn’t crack. The report notes the possibility that, this time, the files were simply carried into the Ecuadorian Embassy by one of Assange’s visitors.

“Both the GRU and WikiLeaks sought to hide their communications, which has limited the Office's ability to collect all of the communications between them,” the report notes. “The Office cannot rule out that stolen documents were transferred to WikiLeaks through intermediaries who visited during the summer of 2016.”

In the end, the most charitable interpretation of Assange’s “dissembling” as Mueller calls it, in the Seth Rich hoax is that he genuinely couldn’t rule out the possibility that Rich was his source. The Mueller report demolished that final moral refuge. Rich had been dead four days when Assange received the DNC files.

WikiLeaks reacted to the Mueller report Thursday with a Trump-like tweet claiming vindication. “WikiLeaks has always been confident that this investigation would vindicate our groundbreaking publishing of the 2016 materials which it has,” the group wrote. Adding a cavieth calling for “full transparency” from the Justice Department.

“We disapprove of the large redactions,” WikiLeaks wrote, “which permit conspiracy theories to abound.”