Mueller gets another witness to flip, charges pile up on Manafort, and Democrats release their memo - here's the latest in the Russia investigation

Special Counsel Robert Mueller secured another potential witness this week in his investigation into Russian interference in the 2016 election.

Rick Gates, the former deputy chairman of the Trump campaign, pleaded guilty on Friday to charges including conspiracy against the US and making a false statement to federal investigators. Gates became the fourth individual known to be cooperating with Mueller.

In addition to Russia election interference, Mueller is also investigating whether President Donald Trump or any members of his campaign colluded with the Russians in their meddling efforts, and whether Trump has obstructed justice at any point during the probe.

Here's more on what you may have missed this week in the Russia investigation:

• Democrats release their memo: Democrats on the House Intelligence Committee released their rebuttal memo to the so-called Nunes memo, pushing back against Republican allegations of surveillance abuse by the FBI and the Department of Justice.
• Mueller levels 32 new charges: Paul Manafort, the former campaign chairman, and Gates were accused in a superseding indictment of misconduct related to tax and bank fraud. The indictment alleges that more than $75 million flowed through the defendants' offshore accounts and that Manafort laundered over $30 million in undisclosed income with Gates's assistance.
• Mueller tries to flip Manafort: Mueller is looking to employ various strategies to convince Manafort to plead guilty to numerous charges related to conspiracy against the US, money laundering, and lying to the FBI. Manafort maintains his innocence and has not only resisted Mueller's overtures, but counter-sued him as well.
• Rep. Devin Nunes launches phase two of his corruption probe: Nunes, the chair of the House Intelligence Committee, sent a list of 10 questions to top US officials to get answers on how they handled information contained in the so-called Trump-Russia dossier. He said he would order subpoenas if his questions aren't answered by March 2.
• Trump rants about Russia: Trump spent the weekend going off about the Russia investigation on Twitter. He also lashed out at Attorney General Jeff Sessions, whom Trump has criticized for recusing himself from overseeing the Russia investigation. Trump questioned why former President Barack Obama didn't do more to prevent Russian interference in the 2016 election, and why the Democratic Party isn't under investigation.
• Why Trump is leveling an unprecedented amount of frustration toward the Russia probe: Experts say Trump has been more vocal than ever about the Russia investigation because Mueller threw a wrench into Trump's most passionate belief about his ascendance to the Oval Office: that he got there on his own merit and without any outside help.
• The White House previews an upcoming report: White House press secretary Sarah Huckabee Sanders gave a cryptic statement about an event "in the coming days" that will demonstrate Trump's tough stance toward Russia. While she did not specify what this event might be, she claimed that Trump "has been tougher on Russia in the first year than Obama was in eight years combined."
• Russians organized real rallies in the US: The Manafort indictments outlined at least nine real rallies that happened in the US, which Russians organized in order to sow discord ahead of the 2016 US election. The Russians communicated with unwitting Trump campaign volunteers to plan demonstrations, according to the indictment.
• Nunes asks Russian bots for help: In a sarcastic tweet on Wednesday, Rep. Devin Nunes called on Russian bots to make a tweet featuring a conservative article go viral in a bid to downplay the impact of these automated and politicized Twitter accounts. These bots, which were deployed starting in May 2014 by the Russian Internet Research Agency, attempted to influence US voters during the 2016 election.
• How Manafort got caught: Investigators were tipped off, in part, about Manafort's illicit activities because he appeared not to know how to convert a PDF document to a Word document. According to the Mueller indictment, Manafort and Gates allegedly emailed back and forth in October 2016 while conspiring to commit bank fraud.

Sonam Sheth contributed to this report.

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