The 20 biggest Trump-Russia bombshells of 2018

Mueller charged 13 Russian nationals and 3 Russian entities for meddling in the election.

In February, Mueller's office charged three Russian entities and 13 Russian nationals with "violating US criminal laws in order to interfere with US elections and political processes."

The charges were directed primarily at the Internet Research Agency (IRA), an infamous Russian "troll factory" located in St. Petersburg that focused on sowing political discord during the 2016 race by using Russian bots to spread fake news and pro-Trump propaganda on Facebook, Twitter, and other social-media platforms.

The 13 Russian nationals charged were indicted for working in "various capacities to carry out" the agency's "interference operations targeting the United States."

Among the defendants was Kremlin-allied Russian oligarch Yevgeniy Viktorovich Prigozhin, who is accused of using his companies, Concord Management and Consulting LLC and Concord Catering, to bankroll the IRA's work.

The charges did not allege that any American was a knowing participant in Russia's activities, or that the underlying conduct altered the outcome of the race.

Mueller later indicted 12 Russian intelligence officers for hacking into the Democratic National Committee.

Mueller's office indicted 12 Russian intelligence officers in July who are suspected of playing a role in the hack of the Democratic National Committee before the 2016 US election.

The charges represented the first time Mueller's office directly pointed a finger at the Russian government for interfering in the election.

The indictment said the conspirators — in this case, the Russia-linked hacker Guccifer 2.0 — communicated with US persons about the release of stolen documents.

In one instance, it said, the conspirator posing as Guccifer 2.0 contacted a person who was "in regular contact with senior members of the presidential campaign of Donald J. Trump."

Rick Gates pleaded guilty and testified against his former boss in a high stakes trial.

Rick Gates, the former deputy chairman of the Trump campaign, pleaded guilty in February and began cooperating with Mueller's office. He was the star witness in the special counsel's case against former Trump campaign chairman Paul Manafort, who went on trial in August for several financial crimes arising from his political consulting work.

At Manafort's trial in August, Gates admitted that he cheated Manafort out of millions of dollars to fund an extramarital affair.

He also testified to several other exchanges with Manafort that appeared to show the two men conspiring to commit bank fraud and tax fraud at Manafort's direction.

Paul Manafort was convicted of a multitude of financial crimes.

Following Gates' testimony and several days of other witness testimony, Manafort was convicted of several counts of tax fraud, bank fraud, and failure to report foreign bank accounts.

Manafort was set to face a second federal trial but struck a plea deal with Mueller's office before going on trial.

Prosecutors have since accused him of breaching his plea deal by lying to investigators after agreeing to cooperate with them, and Mueller was also reportedly furious that Manafort was updating Trump's legal team on everything prosecutors were asking him about after he pleaded guilty.

Mueller is now said to be weighing putting Manafort on trial again.

The FBI raided the property of Trump's lawyer and longtime fixer, Michael Cohen.

The investigations into Trump took on a whole new meaning when it emerged in April that the FBI had raided the home and office of Michael Cohen, then Trump's longtime lawyer and fixer.

Cohen pleaded guilty in two federal criminal probes.

Federal prosecutors snagged a huge victory when they secured two guilty pleas from Cohen.

Cohen, who is a key figure in multiple criminal investigations into him and the president, pleaded guilty to tax evasion, bank fraud, and campaign-finance violations in August as part of a Manhattan US attorney's office investigation.

Cohen said following his guilty plea that he broke election law at Trump's direction.

Last month, he also pleaded guilty to one count of lying to Congress as part of Mueller's investigation. He has been cooperating with both probes since August, and he is believed to be one of the star cooperators against Trump.

Cohen's lawyers said in a sentencing memo earlier this month that Cohen was in "close and regular contact" with the White House while drafting his false testimony.

Trump, for his part, appears to be aware of the danger Cohen poses: he has unleashed a torrent of Twitter rants against his former lawyer, at one point calling him a "rat" and accusing him of being weak.

Cohen has said that he previously felt it was his "duty" to cover up for Trump's "dirty deeds," but that he is now eager to cooperate with the government out of duty to country. He was sentenced to three years in prison last week.

New York federal prosecutors began probing whether Trump Organization execs broke campaign-finance laws.

Investigators began investigating the thread, Bloomberg reported, after Cohen — who is the Trump Organization's former lead counsel — pleaded guilty to tax evasion, bank fraud, and campaign finance violations in August.

Cohen claimed that his campaign finance violations were made "at the direction of the candidate" with "the purpose of influencing the election." Cohen's lawyer, Lanny Davis, confirmed that candidate was Trump.

The Trump Organization's chief bookkeeper began talking to the feds.

Allen Weisselberg, the chief accountant at the Trump Organization, was granted immunity in August in exchange for his cooperation with at least one federal investigation into Trump's business dealings.

Weisselberg was, at the time, one of three key cooperators against Trump. The other two were Cohen and Manafort.

Combined, the three men are privy to some of the most confidential details of the main facets of Trump's life: his personal dealings, his campaign, and his business.

In short, said Elie Honig, a former federal prosecutor, "this is the perfect storm of cooperators."

FBI deputy director Andrew McCabe was fired hours before he was set to retire.

McCabe was fired in March, just one day before he was set to retire.

McCabe was forced out of the FBI earlier in the year amid an internal investigation by the Office of the Inspector General (OIG) into his approval of unauthorized disclosures to the media in October 2016 related to the bureau's Hillary Clinton email probe.

The Department of Justice (DOJ) inspector general Michael Horowitz concluded in a report that McCabe was not forthcoming during the OIG review. The FBI Office of Professional Responsibility (OPR) subsequently recommended that then-Attorney General Jeff Sessions fire McCabe.

McCabe said in a statement afterward: "Here is the reality: I am being singled out and treated this way because of the role I played, the actions I took, and the events I witnessed in the aftermath of the firing of James Comey."

McCabe was one of three top FBI officials former FBI director James Comey told about his conversations with Trump, many of which are now the subject of Mueller's investigation into whether Trump sought to obstruct justice when he fired Comey.

The other two officials Comey told were James Baker, the former FBI general counsel, and James Rybicki, Comey's former chief of staff. Baker was demoted from his position and reassigned within the FBI before leaving, and Rybicki was forced out of the bureau last year.

Trump forced out Jeff Sessions after months of fury that Sessions wasn't reining Mueller in.

Sessions resigned in November after months of speculation about his departure, and one day after the midterm election.

Sessions said in a letter that he was resigning at Trump's request. His resignation came following months of public attacks from the president, who was reportedly long frustrated with Sessions' recusal from the Russia investigation and his refusal to rein Mueller in.

Matthew Whitaker, Sessions' former chief of staff, has since taken over as acting attorney general and has a history of making controversial and antagonistic remarks about Mueller and the Russia probe.

Following Trump's announcement that Whitaker would take over in the interim, there was intense speculation that the president had tapped him specifically to cripple the Russia investigation. As of December, the investigation is still being overseen by deputy attorney general Rod Rosenstein.

Devin Nunes' war on the DOJ reached a climax with the release of a highly controversial memo about FBI surveillance.

The House Intelligence Committee set a remarkable and dangerous precedent when Republicans on the panel released a highly controversial memo that claimed several top officials at the Justice Department and the FBI acted improperly when they signed off on so-called FISA applications seeking extended surveillance of Carter Page, a former Trump campaign adviser.

Intelligence veterans warned against releasing the document, arguing that it contained sensitive information that could endanger US sources and methods.

But as far as its material claims went, the memo was underwhelming to legal experts, who pointed out that it mischaracterized the intelligence community's work and that many of its claims had been debunked.

The House Intelligence Committee released its report on Russian interference in the 2016 election.

The Republican-led House Intelligence Committee released a report of its findings in the panel's Russia probe.

It said Russia was responsible for carrying out cyberattacks against the US, disseminating hacked emails stolen from the DNC, and launching a social media disinformation campaign — findings that largely echo parts of the US intelligence community's assessment of Russia's interference in the 2016 election.

But Republicans' conclusions about whether President Donald Trump's campaign colluded with Moscow left out critical context and painted an incomplete picture of the scope of the campaign's contacts with Russians.

The panel has also been mired in controversy under Nunes' leadership, with Democratic lawmakers saying they've largely been left out of the investigative process and that Republicans have refused to subpoena key witnesses and documents.

Ranking member Adam Schiff has said Democrats plan to relaunch parts of the investigation when they take over as the majority party in the House of Representatives next year.

The Democratic Party sued the Trump campaign, Russia, and WikiLeaks.

The suit was filed in federal court in Manhattan and alleges the Trump campaign worked with WikiLeaks, the Russian government, and the GRU — Russia's military intelligence unit — to hack into the Democratic National Committee in the summer of 2016 and disseminate stolen materials to the public.

The Democratic Party claimed the actions were taken specifically to hurt former Democratic presidential nominee Hillary Clinton's campaign, and that they amounted to an illegal conspiracy to maim the party and sway the election against the Democrats.

One of the Russians who attended the June 2016 Trump Tower meeting admitted to being a Kremlin "informant."

Natalia Veselnitskaya, a Russian lawyer who attended a June 2016 Trump Tower meeting with several top campaign officials, detailed in an interview with NBC News her previously undisclosed relationship with Yuri Chaika, Russia's prosecutor general.

"I am a lawyer, and I am an informant," she said. "Since 2013, I have been actively communicating with the office of the Russian prosecutor general."

Trump and his allies have long denied that the meeting with Veselnitskaya and several others — during which Veselnitskaya offered the Trump campaign dirt on Clinton — had anything to do with the Russian government.

But after Veselnitskaya's remarks aired, Trump appeared to confirm the lobbyist was connected to the Kremlin.

Speaking about the revelation, Trump said, "You know what? If she did that," it was "because Putin and the group said, 'You know, this Trump is killing us. Why don't you say that you're involved with government so that we can go and make their life in the United States even more chaotic.'"

It was the first time Trump acknowledged a link between Veselnitskaya and Putin or the Russian government.

Rudy Giuliani joined Trump's legal team after defense attorney John Dowd's departure.

The former New York City mayor Rudy Giuliani joined Trump's shifting legal team this year after defense attorney John Dowd resigned following months of tension with Trump.

The rift between Trump and Dowd stemmed from Trump's refusal to follow Dowd's advice about avoiding a one-on-one interview with Mueller. Since taking over from Dowd, Giuliani has struck a more aggressive tone toward the special counsel and the Russia probe.

Earlier this year, he told INSIDER the shift was deliberate. "Our jury is the American people," he said. Regardless of what Mueller finds, "if they decide that the president is being badly treated, there's no way any Congress will impeach him."

Giuliani has become more combative in recent weeks, as a multitude of federal criminal investigations into nearly every organization Trump has led — his 2016 campaign, his inaugural committee, the Trump Organization, and the Trump Foundation — close in on the president.

Trump, meanwhile, is also said to be increasingly concerned about being impeached.

Mueller indicted a Russian intelligence operative and close Manafort ally on charges of conspiracy and obstruction.

Mueller, in a June superseding indictment against Konstantin Kilimnik — a Russian-Ukrainian operative and longtime associate of Manafort's — charged the two men with conspiracy to obstruct justice and obstruction of justice.

Mueller's office asked the court in a separate filing to revoke or revise the terms of Manafort's bail at the time in light of allegations that he and Kilimnik attempted to tamper with witness testimony in the Russia probe.

Mueller's indictment represented the first time that an American and a Russian were named as co-defendants.

Trump stunned observers when he sided with Putin over the US intelligence community during their high stakes Helsinki summit.

Immediately after the Helsinki summit, Associated Press White House reporter Jonathan Lemire asked Trump during a joint press conference with Putin who he believed and whether he would publicly denounce Russia's interference in the 2016 US election and warn Putin never to do it again.

Trump declined to do so and appeared to pin the blame on the US.

"We have two thoughts," Trump said. "You have groups that are wondering why the FBI never took the [DNC] server. Why haven't they taken the server? Why was the FBI told to leave the office of the Democratic National Committee? I've been wondering that."

He added: "With that being said, all I can do is ask the question. My people came to me … They said they think it's Russia. I have President Putin. He just said it's not Russia.

"I will say this," Trump said. "I don't see any reason why it would be."

Trump's comments flew in the face of the US intelligence community's findings in January 2017 that the Russian government mounted an elaborate, multifaceted campaign aimed at elevating Trump to the presidency.

Following harsh blowback over his comments, the White House later backtracked and said Trump misspoke and had meant to say he didn't see any reason why it "wouldn't be" Russia that interfered.

Russian national and gun rights activist Maria Butina pleaded guilty to engaging in a conspiracy against the US and began cooperating with investigators.

Maria Butina, who is accused of being a Russian agent, pleaded guilty this month to engaging in a conspiracy against the United States.

Butina is accused of working at the direction of a high-ranking Russian official, believed to be the Putin-friendly banker Alexander Torshin, to infiltrate the National Rifle Association and sway US policy in favor of Russia. Both Butina and Torshin have deep ties to the NRA.

A plea agreement submitted to the court said Butina would "cooperate fully, truthfully, completely and forthrightly with … any and all matters as to which the Government deems the cooperation relevant."

Butina has surfaced as a key figure in investigations into the contacts between Russia-linked individuals and members of the Trump campaign, as well as to other GOP operatives. She could also be a valuable asset to investigators probing whether Russia used the NRA as a conduit to illegally funnel money to the Trump campaign.

Former national security adviser Michael Flynn is set to be sentenced in the Russia investigation.

Michael Flynn, the former national security adviser, is set to be sentenced to prison following nearly a year of full cooperation with federal prosecutors in the Russia investigation, as well as several other open criminal investigations.

In a sentencing memo filed last week, prosecutors recommended that Flynn get little to no jail time, citing the "substantial assistance" he provided to the investigations.

Flynn was among the first defendants to plead guilty in the Russia probe. His sentencing was delayed five times after prosecutors said they needed more information from the former national security adviser, who also served as a key adviser to Trump's 2016 campaign.

In their filing, prosecutors emphasized that Flynn began cooperating early, that his assistance was critical in encouraging other witnesses to come forward and be candid, and that he helped the investigation in several ways.

In a bizarre twist, Mueller's office asked the FBI to investigate claims that women were offered money to falsely accuse him of sexual misconduct.

Mueller's office first learned of the scheme when a woman got in touch with them and said she herself had been offered money to make false claims of sexual harassment against the special counsel.

The special counsel's office was also contacted by several reporters who were told about the alleged scheme by a woman who said a man working for the shady agency Surefire Intelligence and the GOP operative Jack Burkman offered her around $20,000 "to make accusations of sexual misconduct and workplace harassment against Robert Mueller," according to a copy of the email obtained by INSIDER.

Later, The Atlantic reported that a second woman was contacted by someone working for Surefire Intelligence who claimed to be investigating Mueller.

Several journalists said Jacob Wohl, a far-right conspiracy theorist and disgraced former hedge funder, was involved in Burkman's and Surefire Intelligence's alleged scheme.

When contacted by NBC News, Wohl said he didn't have any role in the matter.

But the outlet reported that Wohl's email address is the one listed in the domain records for the firm's website. Calls to a number on the website also reportedly went to a voice mailbox belonging to Wohl's mother.