The sprawling and politically charged probe into alleged Russian interference in the 2016 U.S. presidential election is about to open a significant new chapter with the trial of Paul Manafort, U.S. President Donald Trump's former campaign chairman.
The backdrop: the conclusion by the U.S. intelligence community, issued the same month Trump took office, that Russian President Vladimir Putin ordered a hacking-and-propaganda campaign aimed at not only swaying voters, but also favoring Trump's candidacy.
While questions relating to possible Russian involvement in the 2016 vote will not be on the docket, that backdrop looms large over the proceedings that begin on July 31.
Here is a quick rundown of how we got here, and what to look out for.
First Up, Paul Manafort
On July 31, Manafort will become the first person to go to trial on charges brought by Special Counsel Robert Mueller, who was appointed in May 2017 to investigate alleged Russian election interference, including possible interactions between Trump associates and Russian officials.
Manafort, who served as Trump's campaign manager until he was fired three months before the election following revelations about his work for a Ukrainian political party, was one of the first people charged in Mueller's investigation.
He was indicted in October 2017 on a raft of charges that he violated U.S. banking laws in the course of his work abroad as a lobbyist, prior to his time with the Trump campaign. He has pleaded not guilty to all the charges.
He also stands accused of violating U.S. foreign-agent laws. Those charges, also brought by Mueller's investigators, have been filed in a parallel trial that begins on September 17 in federal court in Washington, D.C., and concern work he did for a Ukrainian political party and its ousted president, Viktor Yanukovych.
His trial this week in U.S. District Court in Alexandria, Virginia, focuses on allegations that he failed to report foreign bank accounts and used shell companies to conceal banking transfers.
Pretrial evidence and affidavits filed in court detail an extensive list of items and purchases that, according to Mueller's investigators, were made using suspect banking transactions. That includes things like antique rugs, tailored suits, season tickets to professional baseball games, and townhouse and real-estate purchases.
Closing Manafort's Circle
Manafort has long worked as a Washington lobbyist, affiliated mainly with Republican causes, and is also connected to powerful businessmen in Ukraine and Russia.
He worked with Oleg Deripaska -- a billionaire Russian aluminum tycoon with close ties to the Kremlin -- on real-estate deals in Manhattan, and on a failed venture to purchase a Ukrainian cable network. The real-estate deal soured, and Deripaska sued Manafort in U.S. court.
Manafort's business dealings also included Ukrainian oligarch Rinat Akhmetov, who was a major financier for former Ukrainian President Yanukovych's Party of Regions.
Yanukovych became Ukraine's president in 2010, and his rule was marked by his administration's closeness to Russia and the jailing of a pro-Western political opponent, Yulia Tymoshenko.
Efforts to sway U.S. and European opinion on Tymoshenko's jailing are the basis for the foreign-agent charges that Mueller has filed in the parallel case to be tried in Washington, D.C.
Yanukovych fled Ukraine in February 2014 after months of street demonstrations in support of a European Union partnership agreement erupted in violent clashes with police. He now lives in exile in Russia.
The charges Manafort faces are serious felonies, but minor when compared with the other legal cases pending, such as the foreign-agent violations.
Taken altogether, however, and along with prosecutors' stated intention to seize basically all of his wealth -- including a life-insurance policy -- Manafort faces not only the possibility of a long prison sentence, but also financial ruin.
Mueller is counting on that prospect as a way to pressure Manafort to provide evidence and testimony that could implicate other people, possibly including more senior Trump associates.
Mueller has already succeeded in pressuring others to cooperate. Manafort's former deputy, Rick Gates, pleaded guilty in February to charges of conspiracy and lying to a federal agent. Gates was among 35 potential witnesses named by Mueller on July 27 who could be called to testify in the Alexandria trial.
Mueller brought added pressure on Manafort last month when he filed additional charges, accusing him of trying to tamper with potential witnesses, and persuaded a judge to revoke his bail. That sent him to jail pending the September trial in Washington, D.C.
The trial is also expected to expose links to other investigations. A judge has granted immunity to five people -- including accountants and bankers -- who have been subpoenaed by Mueller to testify.
Their testimony, and other evidence introduced in trial, could end up shining a light on the core mission of Mueller's investigation: examining the possibility that Trump associates may have sought to collude with Russian, or Russian-linked, individuals to affect the 2016 election.
Perception Is Everything
The ultimate goal for Mueller is a source of major dispute. Some Democrats say that if the investigation uncovers criminal activity by Trump, Mueller should indict the president, even though Justice Department guidance suggests that can't happen.
Republicans generally support Mueller's examination of possible Russian interference, warning Trump against seeking to fire him. Few Republicans, if any, have expressed any enthusiasm for the prospect of Trump being charged.
"From Robert Mueller's perspective, the goal isn't to charge Trump," says Barbara McQuade, who served as U.S. attorney for eastern Michigan between 2010 and 2017. "The goal is to learn the truth, and Paul Manafort is in a position to be able to share what happened."
Whatever the goal, the Manafort trial is crucial to perceptions of Mueller's probe.
Americans are split in their support of his efforts, though a small majority does back it. Trump's most fervent Republican supporters, however, agree with the president's claim that the investigation is a "witch hunt."
"I think prevailing here would be important to the special counsel, to build public confidence," McQuade says. "If a jury were to acquit Manafort, it would further diminish confidence in what the counsel is doing."
Back To Russia
Along with Manafort and Gates, Mueller has to date brought charges against more than 30 entities, including Russian nationals and companies.
The newest charges were filed July 13 against 12 Russian military intelligence officers, whom Mueller accused of interference in the 2016 election.
Those charges dovetail with others filed in February against a group of Russians who allegedly used social media to sow discord and confusion during the election. That group includes Yevgeny Prigozhin, a Russian tycoon known as "Putin's chef" for the catering work his companies have done for the Kremlin.
Through his U.S.-based lawyers, Prigozhin and his company Concord Management and Consulting have denied the charges.
While it's unlikely any of the Russians will end up in a U.S. court, Mueller's filings have laid out detailed evidence for how Russian intelligence agencies and Kremlin-connected businesses allegedly worked to sway U.S. voters.
Additionally, some of Mueller's charges involve "conspiracy," a broader criminal definition that would allow for going after Americans who may have worked with the Russians to influence the 2016 vote.
Another person indicted by Mueller was Michael Flynn, who was fired as Trump's national-security adviser weeks after Trump took office. Flynn pleaded guilty in December 2017 to lying to federal agents about his interactions with Russian officials, including Sergei Kislyak, then Russia's ambassador to the United States.
Like Gates, he has agreed to cooperate with Mueller, according to court filings.
George Papadopoulos, a foreign-policy adviser on the Trump campaign, was charged with lying to FBI agents about his interactions with an academic named Joseph Mifsud. Court documents described Mifsud as connected to the Russian Foreign Ministry.
Still To Come?
Another dimension to the legal issues shadowing Trump's presidency is the possible indictment of Trump's longtime lawyer and "fixer," Michael Cohen. FBI agents raided Cohen's home and offices in April, reportedly based on information provided by Mueller's team.
Volumes of documents, electronic files, computer hard drives, and other materials were seized, and prosecutors from the U.S. attorney's office in Manhattan have been examining the materials.
Cohen has faced scrutiny for his alleged role in possibly arranging for payments to be made to a porn actress who says she had an affair with Trump.
The issue of when and whether the actress, Stephanie Clifford, was paid is important because if the payment was intended to be "hush money" -- aimed at keeping her from speaking publicly about the alleged affair -- and it was made during the 2016 election campaign, federal law requires that it be reportedly publicly.
If Trump authorized the payment but it wasn't disclosed, it could be considered a federal crime.
On July 20, The New York Times and The Wall Street Journal reported that among the files seized in the FBI raid was a secret recording of a conversation Cohen had with Trump in September 2016. In it, a snippet of which has been released, they reportedly discussed payment to another woman who also said she had an affair with Trump.
The U.S. attorney's office in Manhattan is one of the most powerful and influential in the country. Moreover, it is insulated from potential political meddling by the White House, a concern for many given that Mueller assumed responsibility for the Russia investigation only after Trump fired FBI Director James Comey in May 2017.
Trump's shifting explanations for why he fired Comey have fueled suspicions that it was aimed at halting the FBI investigation, which began in July 2016. Some legal experts say that in itself may constitute a federal crime -- obstruction of justice -- an allegation that figured prominently in the impeachment-related proceedings of Presidents Richard Nixon, in 1974, and Bill Clinton, in 1988.
On July 29, Trump claimed in a series of Tweets that he and Mueller had "a very nasty & contentious business relationship" and that the special counsel had other "conflicts of interest" that should bar him from the Russia probe.
While Trump could fire Mueller, as he reportedly tried to do in June 2017, it would be virtually impossible to fire the prosecutors overseeing the Cohen case.
Cohen has indicated he might also cooperate with federal investigators, offering insights into Trump's real-estate empire and its business dealings before Trump became president.
"I think these cases are all intertwined in some ways. They all involved Manafort and financial deals, so things could come out. I don't how closely connected Manafort is with Cohen...but it's possible one thing comes out of another," McQuade says. "What Mueller will put on is enough evidence to prove his case, but not everything he knows about Manafort."