Robert Mueller Getty Images

Special counsel Robert Mueller completed his Russia investigation and delivered his highly anticipated report to Attorney General William Barr on Friday. For nearly two years, Mueller has been investigating Russian meddling in the 2016 presidential election and whether the then-candidate Donald Trump's campaign colluded with the Kremlin. Despite endless media coverage and speculation, Mueller has remained tight-lipped on his findings. Nearly 200 charges against 34 people and three Russian companies have been filed since the beginning of the investigation. Six of those indicted are former Trump advisors. Twenty-six are Russian nationals. So far, seven have submitted guilty pleas, and five have been sentenced for their crimes. Trump and his allies have repeatedly attacked the investigation, calling it a "witch hunt." He has denied any wrongdoing related to the Mueller probe, adopting "no collusion" as a mantra over the course of the investigation. House Speaker Nancy Pelosi has said Trump is "not worth" impeachment, while other Democrats hope the Mueller report provides fodder for his ouster. Separating fact from conjecture can be difficult amid the noise surrounding the investigation. This is what we know about the Russia investigation so far.

Russian election interference

A federal grand jury indicted 13 Russian nationals and three Russian businesses for allegedly interfering in the 2016 presidential elections with the goal of getting Trump elected. A Russian organization called the Internet Research Agency was accused of waging "information warfare" against the U.S. by using fake American online personas and social media platforms to sway voters' opinions. Twelve Russian intelligence officers were also indicted for computer-hacking conspiracies that aimed to meddle in the election. They were accused of hacking Democratic National Committee and Democratic Congressional Campaign Committee emails and staging their release by sharing them with WikiLeaks. Russian President Vladimir Putin claimed any assertions that Russia interfered in the U.S. election are "lies."

Charges against Trump associates

The former Trump associates who have been charged with crimes include Michael Flynn, former national security advisor to Trump's campaign and presidency; Paul Manafort, former Trump campaign chairman; Rick Gates, former deputy Trump campaign chairman; George Papadopoulos, former foreign policy advisor to the Trump campaign; Michael Cohen, Trump's former personal lawyer, and Roger Stone, a longtime Trump associate and former campaign advisor.

Michael Flynn

Former national security adviser Michael Flynn exits a vehicle as he arrives for his sentencing hearing at U.S. District Court in Washington, U.S., December 18, 2018. Jonathan Ernst | Reuters

Flynn was charged with making false statements to FBI agents about his communications with a former Russian ambassador to the U.S., Sergey Kislyak. He lied to Vice President Mike Pence and FBI investigators when he said that he did not discuss sanctions with Kislyak before Trump took office. He pleaded guilty in December 2017 and is awaiting sentencing as he cooperates with Mueller's investigation.

George Papadopoulos

Former Trump campaign aide George Papadopoulos with his wife Simona Mangiante arrives for the sentencing hearing at U.S. District Court in Washington, U.S., September 7, 2018. Yuri Gripas | Reuters

Papadopoulos was charged with making false statements to the FBI about his interactions with a Russia-tied foreign professor who claimed the Kremlin possessed "dirt" on Democratic presidential nominee Hillary Clinton. He pleaded guilty in October 2017 and was released from prison in December 2018 after serving just 12 days out of his two-week prison sentence.

Paul Manafort

Former Trump campaign manager Paul Manafort departs from U.S. District Court in Washington, U.S., February 28, 2018. Yuri Gripas | Reuters

Manafort was charged by Mueller's prosecutors in two federal courts. In U.S. District Court in Alexandria, Virginia, Manafort was convicted in August on eight criminal counts, including bank fraud, tax fraud and failing to file a foreign bank account report. He was sentenced to 47 months in prison on March 13. A week later, Manafort was sentenced to 43 additional months behind bars in federal court in Washington, D.C., where he had pleaded guilty to conspiracy charges. Many of the charges against him were related to income that he earned from work as a political consultant for former Ukrainian President Viktor Yanukovych years before joining Trump's campaign.

Rick Gates

Richard Gates, former associate to Paul Manafort, leaves the Prettyman Federal Courthouse after a hearing February 23, 2018 in Washington, DC. Getty Images

Gates pleaded guilty in February 2018 to two criminal counts, including conspiracy and lying to FBI agents. He had testified against Manafort, his former longtime business partner, in Manafort's trial in Virginia. Gates, who had worked on Trump's campaign and the presidential transition phase even after Manafort left, agreed to fully cooperate with Mueller's probe. He is awaiting sentencing as he continues to cooperate with the special counsel.

Michael Cohen

Michael Cohen, the former personal attorney of President Donald Trump, departs the U.S. Capitol after testifying before a closed House Intelligence Committee hearing on Capitol Hill in Washington, February 28, 2019. Joshua Roberts | Reuters

Cohen, Trump's former attorney, pleaded guilty in August 2018 to making false statements to Congress about efforts to build a Trump Tower in Moscow. He also pleaded guilty to eight counts, including tax evasion, bank fraud and campaign finance violations, in federal court in the Southern District of New York. He was sentenced to 3 years in prison. Cohen's campaign finance violation charges were in regard to his $130,000 hush-money payment to adult film star Stormy Daniels, who claims she had an affair with Trump before the 2016 election. Trump initially denied knowing of the payments, though his current personal attorney Rudy Giuliani said in an interview with Fox News that Trump reimbursed Cohen for the payment to Daniels.

Roger Stone

Roger Stone, longtime ally of U.S. President Donald Trump, arrives for a news conference in Washington, U.S., January 31, 2019. Leah Millis | Reuters

Stone is the most recent Trump associate to be indicted. He was charged in Washington federal court in late January with crimes including lying to Congress and witness tampering. Mueller alleges that Stone misled Congress about his involvement with whistleblower site WikiLeaks, which dumped troves of Democrats' emails that were allegedly hacked by Russian agents. Stone has pleaded not guilty to the charges.

Others charged in the probe