In a piece on Yahoo News, journalist Michael Isikoff reported that Mueller's team is "tying up loose ends" in the Russian Federation probe as they prepare to file three crucial memos this week on their most high profile defendants: Michael Flynn, Paul Manafort and Michael Cohen. He has pled guilty to those lies. One knowledgeable source said the bulk of Flynn's cooperation with the special counsel occurred immediately following his December court appearance. The special counsel in the Russian Federation investigation is set to give the first public insight into how much valuable information President Donald Trump's former national security adviser has shared with prosecutors.
The news is not entirely unexpected.
As Mueller is expected to be close to the end of his investigation, the president has doubled down on his attacks of the probe, which he has repeatedly referred to as a "witch hunt".
Flynn has been working with Mueller's team since last December, after he pleaded guilty to lying to the Federal Bureau of Investigation.
Flynn was forced to resign his post on February 13, 2017, after news reports revealed that Obama administration officials had warned the Trump White House about Flynn's false statements.
The filing recommends that Flynn's sentence, which he will receive for pleading guilty to lying to the Federal Bureau of Investigation, can be substantially shortened because of his extensive cooperation with the probe.
Flynn, who turns 60 on Wednesday, is among a number of people in Trump's orbit who have pleaded guilty to criminal charges.
As part of Flynn's plea deal, he agreed to cooperate with Mueller's office on "any and all matters" deemed relevant.
The memo said prosecutors can't reveal the extent of his cooperation because "the investigations in which he has provided assistance are ongoing".
The national security experts at Lawfare wrote, moreover, that the public might also learn more "in the context of that briefing about the relationship Manafort appears to have maintained, through counsel, with the White House after his plea and cooperation agreement".
Mueller's team is looking into whether Stone, an informal adviser to Trump during the 2016 campaign, was in communication with WikiLeaks before the website publicized stolen emails from Hillary Clinton's presidential campaign.
Cohen last week said he had lied to Congress about Trump's plans to build a tower in Moscow in 2016. He accused Cohen of making up "stories to get a GREAT & ALREADY reduced deal for himself" and should, "in my opinion, serve a full and complete sentence".