Nearly a year ago, an investigation led by special counsel Robert Mueller was tasked by Deputy Attorney General Rod Rosenstein with exploring any links or coordination between the Russian government and “individuals associated with the campaign of President Donald Trump,” and, additionally, “any matters that arose or may arise directly from the investigation,” according to the appointment order.

Since the order was issued on May 17, 2017, the investigation has grown into a multipronged effort that has resulted in criminal proceedings against 19 people — five U.S. nationals, 13 Russians and one Dutch national — and three Russian organizations.

Here are four areas of the investigation:

A court artist drawing shows President Donald Trum FILE - A court artist drawing shows President Donald Trump's former campaign chairman, Paul Manafort, center standing and Manafort's business associate, Rick Gates, in federal court in Washington, Oct. 30, 2017, before U.S. Magistrate Judge Deborah A. Robinson. FILE - A court artist drawing shows President Donald Trump's former campaign chairman, Paul Manafort, center standing and Manafort's business associate, Rick Gates, in federal court in Washington, Oct. 30, 2017, before U.S. Magistrate Judge Deborah A. Robinson.

?Trump campaign officials’ business deals involving Russia

Perhaps the most visible results of the investigation so far are the indictments of former Trump campaign chairman Paul Manafort and his business partner, Paul Gates.

On Oct. 30, 2017, Manafort and Gates surrendered to FBI agents to face charges they conspired to launder money, failed to file reports of foreign bank and financial accounts, acted as unregistered agents of foreign principal, and made false statements, including statements under the Foreign Agent Registration Act. The charges were related to consulting work they did for pro-Russian businesspeople in Ukraine. Gates has pleaded guilty, while Manafort maintains his innocence.

CNN has reported that the FBI is looking for suspicious ties between Trump and Russia in financial records related to the Trump Organization (the collective name of a group of some 500 business entities owned solely or principally by President Trump), Trump himself, his family members, and his campaign associates.

Transactions under investigation include Russian purchases of Trump apartments, a New York City development with Russian associates, the 2013 Miss Universe pageant in Moscow, and Trump’s sale of a Florida mansion to Russian oligarch Dmitry Rybolovlev for $30 million more than its appraised value.

FILE - Russian Ambassador to the U.S. Sergei Kisly FILE - Russian Ambassador to the U.S. Sergei Kislyak arrives at the State Department in Washington, July 17, 2017. FILE - Russian Ambassador to the U.S. Sergei Kislyak arrives at the State Department in Washington, July 17, 2017.

?Russian campaign contacts

In addition, the probe is looking at contacts between Russian government officials and Trump campaign officials.

George Papadopoulos, a former Trump foreign policy adviser, pleaded guilty Oct. 5, 2017, to making false statements to FBI agents about contacts he had with agents of the Russian government while working for the Trump campaign in 2016. He is cooperating with Mueller’s investigators.

Former National Security Adviser Michael Flynn pleaded guilty Dec. 1, 2017, to “willfully and knowingly” making “false, fictitious and fraudulent statements” to the FBI about contacts and communications with Russia’s then-ambassador to the United States, Sergey Kislyak. Kislyak returned to Russia in August 2017 and now serves in the Russian legislature.

On Feb. 16, 2018, Mueller issued indictments for 13 Russian citizens and three Russian entities regarding campaign contacts, plus released new charges against Manafort and Gates on February 22.

FILE - people stand outside the Democratic Nationa FILE - People stand outside the Democratic National Committee (DNC) headquarters in Washington. FILE - People stand outside the Democratic National Committee (DNC) headquarters in Washington.

Russian attempts to influence US voters through cyberspace

In January 2017, U.S. intelligence agencies concluded “with high confidence” that the Russian government interfered with the U.S. election by hacking into the computers of the Democratic National Committee and John Podesta, campaign chairman for Democratic candidate Hillary Clinton. The hackers then forwarded the contents of the emails to WikiLeaks.

NBC has reported Mueller is assembling a case against Russians who carried out the hacking and leaking of private information “designed to hurt Democrats in the 2016 election.” NBC said potential charges include violations of statutes on conspiracy, election law, and the Computer Fraud and Abuse Act.

Beyond the targeted hacking, Mueller’s team is investigating at least one Russia-based “troll farm” — a group or organization intentionally posting inflammatory comments on social media to disrupt an online community — known as the Internet Research Agency.

In February, a federal grand jury issued indictments for 13 Russian nationals and three Russian entities, alleging they pretended to be Americans online, creating posts that were meant to “sow discord” within the American political system and “spread distrust toward the candidates and the political system in general.” The eight-count indictment charges that by early to mid-2016, the defendants were using their online identities to support Trump’s candidacy and disparage his challenger, Clinton.

The indictment also alleges the defendants encouraged minorities not to vote, or to vote for a third-party candidate.

FILE - Alexander Nix, CEO of Cambridge Analytica, FILE - Alexander Nix, CEO of Cambridge Analytica, arrives at the offices of Cambridge Analytica in London, March 20, 2018. FILE - Alexander Nix, CEO of Cambridge Analytica, arrives at the offices of Cambridge Analytica in London, March 20, 2018.

On Dec. 14, 2017, the Wall Street Journal reported Mueller had requested that data analysis firm Cambridge Analytica turn over the emails of any of its employees who worked on the Trump campaign.

In 2018, Cambridge Analytica was found to have inappropriately acquired the personal information of more than 50 million Facebook users while working on Trump’s presidential campaign. Having also done work for a pro-Brexit campaign in Britain, the company is now the subject of investigations in both countries.

Cambridge Analytica announced Wednesday it was filing for bankruptcy and shutting down.

Former FBI director James Comey arrives for an app FILE - Former FBI director James Comey arrives for an appearance on "The Late Show with Stephen Colbert" at the Ed Sullivan Theater, April 17, 2018, in New York. FILE - Former FBI director James Comey arrives for an appearance on "The Late Show with Stephen Colbert" at the Ed Sullivan Theater, April 17, 2018, in New York.

?Obstruction of justice

A fourth prong of the special counsel investigation is whether the Trump administration obstructed justice with requests to federal law enforcement agencies to state that there was no collusion between the Trump campaign and Russia.

Part of that investigation centers on whether the firing of FBI Director James Comey in May 2017 amounted to obstruction of justice, after, according to Comey, Trump tried and failed to get Comey to swear to the president a vow of loyalty and to end an investigation of former National Security Adviser Flynn, who was fired in February 2017.

The Mueller team has Comey’s personal notes on his interactions with the president while head of the FBI, but a federal judge has denied multiple Freedom of Information Act requests to make the notes public.

Meanwhile, Comey has released his own version of what took place between him and the president in a memoir released last month titled, A Higher Loyalty. The volume of preorders drove the book to No. 1 on Amazon.com’s bestseller list, four weeks before its April 17 release.