WASHINGTON -- It’s been 15 months since Robert Mueller was named special counsel.

Any day now, he and his team could release the findings of their investigation into Russian interference in the 2016 election and whether the Trump campaign played a role in it.

How it began

On May 17, 2017, a special counsel was appointed by Deputy Attorney General Rod Rosenstein.

“My decision is not a finding that crimes have been committed or that any prosecution is warranted,” Rosenstein said in a statement. “The public interest requires me to place this investigation under the authority of a person who exercises a degree of independence from the normal chain of command.”

That person was Mueller.

He’s the second longest-serving FBI director in history – nominated by George W. Bush and holding the title through Obama’s first two years.

Before that, Mueller was a U.S. attorney for more than a decade in Washington, D.C., Massachusetts and California.

He’s also a decorated marine who was awarded a Bronze Star and Purple Heart, among other honors, for his service in Vietnam.

The decision came just days after President Trump fired FBI Director James Comey, and as reports began surfacing that Trump asked Comey to stop investigating his former national security adviser, Michael Flynn.

Attorney General Jeff Sessions had already recused himself from the Russia investigation after not disclosing he met with Russia’s ambassador to the U.S. during the 2016 campaign.

The numbers

The special counsel’s investigation has, so far, produced nearly 200 criminal charges against 32 people and three businesses.

Five people have pleaded guilty to crimes; including three former Trump associates (former campaign adviser George Papadopoulos, former national security advisor Michael Flynn, and former campaign adviser Rick Gates).

On August 21, 2018, a jury in Alexandria, Virginia found a fourth former Trump associate, former campaign chairman Paul Manafort, guilty.

And 25 Russian citizens and three Russian businesses face charges for meddling in the 2016 U.S. election.

The timeline -- 2017

Mueller’s probe started in May 2017 and soon expanded to look into whether Trump obstructed justice.

He filed charges of financial crimes on October 30, 2017 against Manafort and Gates – who ran the Trump campaign for five months in 2016.

That same day, Papadopoulos pleaded guilty to lying to the FBI about his contacts with Russian officials.

And on December 1, 2017, Flynn pleaded guilty to making false statements to the FBI about his conversation with Russia’s U.S. ambassador.

He’s been cooperating with the special counsel since.

The timeline -- 2018

The New Year brought with it a new list of developments.

On February 16, 2018, 13 Russians and three Russian companies were charged with meddling in the 2016 U.S. election through social media.

That same day, a California man, Richard Pinedo, pleaded guilty to identity fraud for selling false bank accounts, including to some Russians.

Just days later, on February 20, 2018, Dutch lawyer Alex van der Zwaan, who has ties to Russia, pleaded guilty to lying to investigators about his work and his communications with Gates.

On February 22, 2018, Mueller added 32 new charges against Manafort and Gates. But then Gates flipped on the next day, pleading guilty to lying to investigators and conspiracy.

Less than two months later, on April 3, 2018, van der Zwaan was sentenced to 30 days in prison and received a fine of $20,000. He becomes the first person to be sentenced in the Mueller probe.

Then on June 8, 2018, Mueller hit Manafort again with charges of witness tampering. That led a judge to revoke Manafort’s bail, end his house arrest, and send him to jail to wait for his August trial to start.

The special counsel also charged one of Manafort’s former aides, Konstantin Kilimnik. He worked for Manafort in Ukraine and potentially has ties to Russian intelligence.

One month later, on July 13, 2018, Mueller charged 12 more Russians with hacking the Democratic National Committee during the 2016 election.

Things intensify

As a Virginia jury deliberated Manafort’s fate in August, The New York Times reported White House lawyer Don McGahn has been cooperating extensively with Mueller.

On August 21, 2018, the 12-person jury found Manafort guilty of eight of the 18 financial crimes he was charged with. Gates was the government’s star witness.

Manafort faces another trial in Washington, D.C. in mid-September.

That same day, Michael Cohen, Trump’s former personal attorney, pleaded guilty in Manhattan federal court to eight counts of his own financial crimes. He also implicated Trump in his courtroom statement.

Mueller had previously handed over the investigation into Cohen to prosecutors in New York.

A lawyer for Cohen has said his client has information that will be ‘of interest’ to the special counsel.

Trump’s role

Through it all, the president has been calling the investigation a witch hunt.

Trump is still debating whether to sit down with Mueller for an interview – something his personal attorney, Rudy Giuliani, has said could be a perjury trap.

In a recent interview with Reuters, Trump claimed he could run the probe himself.

On August 29, Trump announced White House Counsel Don McGahn would be leaving his position in the fall.