Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE’s investigative team saw a flurry of activity in the final weeks of 2018, as the special counsel’s probe passed the 18-month mark in what has become a sprawling investigation into possible collusion between Trump’s 2016 campaign and Russia.

More than two dozen Russian nationals and entities have been charged for their alleged efforts to interfere in the 2016 election, and Mueller has indicted individuals with ties to the Trump campaign and administration.

ADVERTISEMENT

Those swept up in the high-profile investigation range from President Trump Donald John TrumpBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Military leaders asked about using heat ray on protesters outside White House: report Powell warns failure to reach COVID-19 deal could 'scar and damage' economy MORE’s longtime personal lawyer Michael Cohen to lesser-known figures like Alex van der Zwaan, who pleaded guilty to making false statements to investigators.

Trump has repeatedly attacked the probe as a “witch hunt,” while Mueller has remained tight-lipped throughout, largely choosing to speak by way of court filings and criminal charges.

As the investigation heads into 2019, here is a timeline of the biggest developments.

May 17, 2017: Mueller appointed special counsel

Deputy Attorney General Rod Rosenstein Rod RosensteinDOJ kept investigators from completing probe of Trump ties to Russia: report Five takeaways from final Senate Intel Russia report FBI officials hid copies of Russia probe documents fearing Trump interference: book MORE announces Mueller’s appointment to oversee the investigation into Russia’s interference in the 2016 presidential election, a move that comes almost immediately after Trump fires James Comey James Brien ComeyBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Michael Cohen book debuts at top of bestseller list Trump offered Kelly FBI director's job, demanded loyalty: report MORE as FBI director.

June 14, 2017: Possible obstruction of justice

The Washington Post reports that Mueller is investigating Trump for possible obstruction of justice. The article follows Comey’s testimony before the Senate Intelligence Committee in which he said the president asked him in February to end the FBI's investigation into former national security adviser Michael Flynn.

The FBI’s probe into the retired three-star general centered on whether he misled Vice President Pence about his contacts with Russian diplomats before Trump’s inauguration.

July 19, 2017: Trump warns Mueller against investigating his finances

The president sends a warning shot to Mueller in a New York Times interview, stating that the special counsel would be crossing a red line if he probes the Trump family’s financial history.

“I think that’s a violation,” Trump tells the Times. “Look, this is about Russia.”

July 26, 2017: Feds raid Manafort’s house

Federal investigators raid Paul Manafort Paul John ManafortBannon trial date set in alleged border wall scam Conspicuous by their absence from the Republican Convention Ukraine language in GOP platform underscores Trump tensions MORE’s home in Alexandria, Va., marking an escalation against the former Trump campaign chairman. The agents reportedly had a search warrant to seize materials from Manafort's residence.

"FBI agents executed a search warrant at one of Mr. Manafort's residences," Manafort’s spokesman confirms in a statement.

Oct. 30, 2017: Manafort and Gates indicted, Papadopoulos’s guilty plea revealed

Mueller’s first indictment results in 12 counts against Manafort, including conspiracy against the United States, tax fraud and money laundering. Manafort’s former business partner, Richard Gates, is hit with five counts.

ADVERTISEMENT

The charges relate to work done by Manafort and Gates on behalf of a pro-Kremlin political party in Ukraine. Mueller alleges that Manafort and Gates received tens of millions of dollars for their work on behalf of the party, money which they then laundered “in order to hide Ukraine payments from United States authorities.”

The indictment makes no mention of Manafort’s work for Trump’s campaign, and both Manafort and Gates plead not guilty to the charges.

Separately, prosecutors reveal that former Trump campaign aide George Papadopoulos pleaded guilty to lying to investigators a month earlier about conversations he had with a Russian-linked professor who told him Moscow had thousands of emails containing "dirt" on Democratic presidential candidate Hillary Clinton Hillary Diane Rodham ClintonBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Virginia Democrat blasts Trump's 'appalling' remark about COVID-19 deaths in 'blue states' The Hill's Campaign Report: Biden asks if public can trust vaccine from Trump ahead of Election Day | Oklahoma health officials raised red flags before Trump rally MORE — a statement that was made before WikiLeaks published a tranche of Democratic emails.

The charges hit close to home for Trump, particularly because all three men served on his campaign. Still, the White House maintains the charges have nothing to do with the president.

Dec. 1, 2017: Flynn pleads guilty, agrees to cooperate

Flynn pleads guilty to lying to FBI agents, making him the first Trump administration official swept up in the Mueller probe. He left the administration in February 2017.

As part of his plea deal, Flynn agrees to fully cooperate with the special counsel’s investigation.

Feb. 16, 2018: Mueller indicts 13 Russians, three Russian entities

Mueller charges 13 Russian nationals and three Russian groups with interfering in the 2016 U.S. elections, marking a turning point in the investigation.

The explosive allegations say the indicted Russians began their efforts in 2014 by creating false personas and stealing the identities of U.S. residents in order to interfere with the election, aligning Mueller’s charges with an assessment previously reached by U.S. intelligence agencies.

The Russians’ efforts are allegedly tied to the Internet Research Agency, a Russian operation based in St. Petersburg that leveraged Facebook and other U.S. social media platforms to spread divisive messages leading up to the election.

Feb. 20, 2018: Van der Zwaan pleads guilty

Van der Zwaan, an attorney who communicated with Gates, pleads guilty to making “materially false, fictitious, and fraudulent statements and representations” to the special counsel’s office and FBI agents, according to court filings.

Van der Zwaan allegedly lied about his last communications with Gates and then deleted emails requested by the special counsel’s office, according to the indictment.

Feb. 22, 2018: Mueller files new charges against Manafort and Gates

Mueller returns a whopping 32-count superseding indictment against Manafort and Gates, charging the two former campaign aides with committing tax fraud, failing to file reports on foreign bank and financial accounts, and bank fraud conspiracy.

"Manafort and Gates generated tens of millions of dollars in income as a result of their Ukraine work,” the indictment says. “From approximately 2006 through the present, Manafort and Gates engaged in a scheme to hide income from United States authorities, while enjoying the use of the money."

Twenty-three of the counts in the new indictment apply to Gates, while 13 pertain to Manafort.

Feb. 23, 2018: Gates pleads guilty

One day after Mueller filed the superseding indictment, Gates pleads guilty to two charges brought against him by Mueller’s team: one count of conspiracy against the U.S. and one count of making a false statement to the FBI agents investigating Russian interference.

As part of the plea deal, Gates agrees to cooperate “fully, truthfully, completely, and forthrightly” with the special counsel’s office as well as other law enforcement officials, according to court documents filed at the time.

Gates lied to federal investigators about a March 2013 meeting during which Manafort, an unnamed member of Congress believed to be Rep. Dana Rohrabacher Dana Tyrone RohrabacherDemocrat Harley Rouda advances in California House primary Lawyers to seek asylum for Assange in France: report Rohrabacher tells Yahoo he discussed pardon with Assange for proof Russia didn't hack DNC email MORE (R-Calif.), and an unnamed lobbyist discussed Ukraine, the documents say.

Legal experts tell The Hill at the time that Mueller appears to be stepping up the pressure in order to get Gates to flip on Manafort and cooperate with his investigation.

April 3, 2018: Van der Zwaan sentenced to prison

Van der Zwaan is sentenced to 30 days in prison for lying to federal investigators, marking the first criminal sentence to result from Mueller’s probe.

The London-based lawyer is also ordered to pay $20,000 in fines. He was later deported from the U.S.

April 9, 2018: Investigators raid Cohen’s residence, office

Federal investigators raid the apartment, hotel room and office of Michael Cohen, Trump's personal lawyer, reportedly to obtain records related to the 2005 “Access Hollywood” tape released shortly before the 2016 election as well as other evidence that may have been concealed because it was considered damaging to Trump during the election.

June 8, 2018: Mueller files new charges against Manafort and longtime aide

Mueller files a superseding indictment in a Washington, D.C., federal court, bringing two new counts against Manafort and his longtime aide Konstantin Kilimnik, adding to five previously issued charges.

The special counsel alleges that Manafort and Kilimnik, who ran the Kiev office of Manafort’s political consulting company Davis Manafort Partners, obstructed justice and conspired to obstruct justice by trying to coach — or even “prevent” — the testimonies of two witnesses involved in the case.

July 13, 2018: Mueller indicts 12 Russians in 2016 DNC hack

Mueller indicts 12 Russian intelligence officers in the 2016 hack of the Democratic National Committee (DNC), accusing them of conspiring to interfere in the heated presidential race.

All 12 of the defendants are members of the GRU, Russia’s military intelligence agency, according to the indictment. Eleven are charged with conspiring to hack into networks used by the DNC as well as the Democratic Congressional Campaign Committee, while the 12th individual is charged with conspiring to hack into systems used to administer elections, including hacking into a website of a state elections board and sending spear-phishing emails to state elections officials.

The charges mark the first time that onetime Trump campaign adviser Roger Stone Roger Jason StoneJustice IG investigating Stone sentencing: report Romney says Trump's protest tweets 'clearly intended to further inflame racial tensions' Bannon trial date set in alleged border wall scam MORE appears to be mentioned in a court document. While not named, a person fitting Stone’s description is described in the filing as having sent messages that matched the correspondence previously released by the president’s longtime ally.

Stone denies that he was the person in the document, but later acknowledges he was likely the person referenced. He also says he believes he will be indicted in the Mueller investigation.

Aug. 21, 2018: Manafort found guilty, Cohen pleads guilty

A federal jury in a Virginia courtroom finds Manafort guilty of eight charges of bank and tax fraud — five charges of filing false income tax returns, one count of failing to report foreign bank accounts and two counts of bank fraud.

The judge declares a mistrial on the remaining 10 counts — three counts of failing to report foreign bank accounts, five counts of bank fraud conspiracy and two counts of bank fraud.

Separately, Cohen pleads guilty to eight counts total, including five counts of tax evasion and one count of making a false statement to a financial institution, delivering what is viewed as a significant legal blow to Trump.

He also pleads guilty to one count of making an excessive campaign contribution on Oct. 27, 2016, the same date Cohen finalized a payment to adult-film actress Stormy Daniels as part of a nondisclosure agreement over an alleged affair with Trump more than a decade ago.

While he does not mention Trump by name, Cohen says he made the payment at the direction of “a candidate for federal office.”

Sept. 7, 2018: Papadopoulos is sentenced to serve 14 days in prison

Papadopoulos is sentenced to 14 days in federal prison and one year of supervised release for lying to FBI investigators about his Russia contacts.

The former Trump campaign foreign policy adviser is also sentenced to 200 hours of community service.

“I made a terrible mistake for which I paid dearly,” Papadopoulos says in court before his sentence is handed down. “I was not honest, and I may have hindered the investigation.”

Sept. 14, 2018: Manafort pleads guilty, agrees to cooperate

Manafort pleads guilty to two federal charges in a deal that includes cooperating “fully, truthfully, completely, and forthrightly” with the Justice Department in any and all matters that the government finds his cooperation to be relevant.

The former campaign chairman agrees to submit to interviews with Mueller, testify in any future cases and provide related documents.

Manafort also agrees to forfeit several properties and the current funds held in several bank accounts.

Oct. 26, 2018: Mueller reportedly questions Stephen Bannon

Former White House chief strategist Stephen Bannon reportedly meets with the special counsel’s team, who questions him about comments made by Stone suggesting he had prior knowledge of the WikiLeaks release of Democratic emails.

The interview comes amid increasing scrutiny of Stone, who claims he did not have knowledge of WikiLeaks’ inner workings, but rather had a source who let him know the organization had information that would “roil” the 2016 presidential election.

Nov. 7, 2018: Matthew Whitaker plans to take oversight role in Mueller’s probe

Whitaker’s appointment as acting attorney general draws condemnation from Democrats and other critics, who point to his public criticism of the Mueller probe before he joined the Justice Department as chief of staff to now-former Attorney General Jeff Sessions Jefferson (Jeff) Beauregard SessionsTrump's policies on refugees are as simple as ABCs Ocasio-Cortez, Velázquez call for convention to decide Puerto Rico status White House officials voted by show of hands on 2018 family separations: report MORE.

The move means Rosenstein will no longer oversee the Russia investigation after about 18 months doing so.

Nov. 12, 2018: Stone associate reveals possible charges

Jerome Corsi, a right-wing conspiracy theorist and author, reveals that the special counsel’s office had contacted him about a potential plea deal.

Corsi, an associate of Stone, says he had been cooperating with the special counsel’s office for two months and had testified before its grand jury. Still, he says prosecutors were alleging that he had made false statements, and had offered him a deal that would allow him to avoid a prison sentence in exchange for a guilty plea.

Nov. 20, 2018: Trump submits written answers to Mueller

Trump submits a series of written answers to Mueller, which cover "issues regarding the Russia-related topics of the inquiry,” Trump's personal lawyer Jay Sekulow says.

The submission comes after months of wrangling between special counsel and the president's legal team about what answers Trump would provide for investigators, particularly because the president’s attorneys have maintained they would answer questions only pertaining to Russia, not inquiries about whether Trump obstructed the federal investigation into the interference.

Nov. 29, 2018: Cohen pleads guilty

Cohen pleads guilty to making a false statement to Congress about the negotiations surrounding building a Trump Tower in Moscow during the 2016 presidential campaign.

Cohen says he made the misstatements while testifying before two congressional intelligence committees in 2017 about the timing of the project.

Dec. 4, 2018: Mueller recommends no jail time for Flynn

Mueller recommends no prison time for Flynn, citing his “substantial assistance” in the Russia investigation and other ongoing probes.

In a court filing, Mueller says it would be “appropriate” for the judge to impose a sentence for Flynn that does not include prison time. Federal sentencing guidelines called for Flynn to be sentenced to as many as six months in prison and face up to a $9,500 fine.

Dec. 7, 2018: New York prosecutors recommend “substantial term of imprisonment” for Cohen

Federal prosecutors in New York recommend Cohen receive “substantial” prison time for several federal crimes, despite his cooperation with ongoing law enforcement investigations, and Mueller’s probe.

In a filing, prosecutors with the U.S. attorney’s office in the Southern District of New York say Cohen has cooperated with law enforcement in “ongoing matters,” but they emphasize the seriousness of his crimes warrant a “substantial term of imprisonment.”

Mueller files a separate memo, stating he is not taking a position on what Cohen’s sentence should be, but adds that "any sentence of incarceration" that the N.Y. court recommends would be "appropriate."

Separately, prosecutors file a report stating Manafort lied to them about his contacts with the White House and with an associate with suspected ties to Russian intelligence.

The heavily redacted document comes a week after prosecutors had indicated they were weighing new charges against Manafort for breaching their plea deal.

On the same day, Trump announces he will nominate former Attorney General William Barr to lead the Justice Department, a move that would presumably give Barr oversight of the Mueller investigation.

Dec. 12, 2018: Cohen sentenced to three years in federal prison

The sentencing stems from eight federal charges that he pleaded guilty to in August, including campaign finance violations tied to a scheme to pay off women alleging affairs with Trump and charges of lying to Congress about plans to build a Trump property in Moscow that he pleaded guilty to in November.

Cohen, who will be allowed to voluntarily surrender to federal authorities on March 6, is also ordered to pay $1.4 million in restitution, forfeiture of $500,000 and a fine of $50,000.

December 18, 2018: Flynn sentencing trial postponed after scathing remarks by judge

Flynn requests a postponement of his sentencing for lying to FBI agents until his cooperation with federal prosecutors is complete.

The surprise decision by Flynn’s defense attorneys follows U.S. District Judge Emmet Sullivan’s admonishment of Flynn for committing a “serious offense” by lying to investigators about his discussions with then-Russian Ambassador Sergey Kislyak about sanctions on Moscow while serving in a high-level role at the White House.

Sullivan asks Flynn and his counsel whether they want to delay the sentencing, seemingly hinting that Flynn would face a tough sentence if the decision were to go through that day. Flynn and his team then request a postponement, and it is granted.

Dec. 20, 2018: House Intel votes to hand over Stone transcript to Mueller

The House Intelligence Committee, which had interviewed Stone last year as part of its own investigation into Russia's election interference, votes during a closed-door meeting to release the official transcript of Stone’s testimony to the special counsel’s team.

Stone hits back, demanding that the entirety of his official transcript be made public immediately. The committee has previously voted to release the transcripts, and the documents are currently under review by the Office of Director of National Intelligence.