The decision Tuesday by a federal court jury to find former Trump presidential campaign chairman Paul Manafort guilty on eight counts of tax evasion and bank fraud opens the door to a new act in the drama surrounding Special Counsel Robert Mueller’s investigation of Russia’s interference in the 2016 U.S. presidential election.

Jurors could not agree on a unanimous verdict on 10 other charges against Manafort and a mistrial was declared on those charges.

Mueller’s aggressive pursuit and prosecution of Manafort is a clear indication that the special counsel believes Manafort holds answers to key questions about two subjects: Russian election meddling, and whether Donald Trump or anyone on his campaign team broke any laws by conspiring with Russians to work together to make Trump president.

Manafort, 68, could spend the rest of his life in prison if his convictions are upheld on appeal. That gives Mueller leverage to pressure Manafort to cooperate and present potentially incriminating evidence against President Trump or his campaign, in return for a lighter sentence.

In addition, the trial that ended in Manafort’s conviction in U.S. District Court in Alexandria, Virginia was just the first of two trials for the former Trump campaign chairman.

Manafort faces serious charges in an upcoming trial in U.S. District Court in Washington. The tax and bank fraud charges Mueller was convicted of in Virginia mention Russians only in passing. But Russians are prominently featured in Manafort’s upcoming trial in Washington.

The charges against Manafort in the nation’s capital focus on Manafort’s actions in allegedly generating over $60 million in illegal unregistered lobbying income from Russian surrogates and wealthy business owners – known as oligarchs – with strong ties to Russian President Vladimir Putin.

The indictment alleges that Manafort, his employee Rick Gates (who has pleaded guilty to charges) and a Russian operative laundered the illicit money through various shell corporations without paying U.S. taxes.

Now that key witnesses wait in the wings and Russian espionage has been very clearly established as interfering in our 2016 election, Mueller needs to “flip” the one person who had the strongest ties to Russia and Putin via his oligarch friends and benefactors. Paul Manafort is that person – making him a key figure to solve the Russian puzzle.

If Mueller can get the now-convicted Manafort to flip and become a witness, the special prosecutor could then use that evidence in his report at the end of his long investigation. Democrats in Congress could then try to use the report to impeach the president and force him from office.

The prospect of a successful impeachment and conviction of President Trump would increase should Democrats capture majorities in the House and Senate in the Nov. 6 midterm elections. And if he were forced out of office, Trump could be charged criminally for allegedly illegal activity if the evidence warranted.

To be clear, the charges that Manafort was convicted of in Virginia have nothing to do with the five months he spent working as a volunteer on the Trump presidential campaign. Instead, Manafort’s convictions deal his private business activities, some going back many years.

But now that he has been convicted and is awaiting sentencing, Manafort has a lot bigger incentive to cooperate with Mueller’s investigation – something he has refused to do up to now.

Some of President Trump’s supporters say Manafort is being targeted by Mueller as a casualty of a political “witch hunt.”

President Trump himself expressed sympathy for Manafort recently, telling reporters at the White House that Manafort “happens to be a very good person, I think it’s very sad what they’ve done to Paul Manafort.”

Others consider Manafort a willing pawn in Russian President Vladimir Putin’s effort to sow chaos in our 2016 election and elect Trump.

From my perspective as a former FBI special agent of 24 years and former state prosecutor, I view Manafort as a seedy white-collar criminal who is an actor in a stage production with numerous subplots and dozens of complex characters.

The central question Mueller is seeking to answer for the American public is this: Did members of the Trump campaign collude with Putin’s surrogates by agreeing to accept dirt on Hillary Clinton and possibly in other ways in exchange for favorable policy changes towards Russia if Trump became president – especially easing economic sanctions on Russia?

Based on his relationship with Russian surrogates through his lobbying work for former Ukrainian dictator and Putin puppet Victor Yanukovych for over 10 years, Manafort may have some answers.

It is clear to any experienced investigator that the charges filed against Manafort in his two trials are a no-holds-barred means to secure his cooperation and testimony. While perhaps shocking to many, this is how complex conspiracies are unraveled: flip the inside operatives against people higher up the food chain.

Such cases are never made with documents alone. Juries are confused by obscure investigative “paper chases.”

If the U.S. Justice Department had employed similar tactics in the Hillary Clinton email and Clinton Foundation investigations – instead of gratuitously handing out immunity, permitting the selective destruction of critical evidence and severely limiting the scope of the investigations – rational observers may be less prone to see partisanship in the Manafort prosecution.

What also severely detracts from the prosecution is the manner in which former FBI Director James Comey’s inner circle operated during the course of the Clinton and Trump investigations by leaking, lying and using tainted “opposition research’ assembled by former British spy Christopher Steele, whose work was being funded by the Clinton campaign.

Special Counsel Mueller shouldn’t be faulted for doing his job in conducting an aggressive investigation of Russia’s election interference and utilizing every tool lawfully available to federal investigators. He was not the FBI director when the hapless Clinton investigations were conducted amid hundreds of leaks and the partisan antics by the Obama administration, the Justice Department under Attorney General Loretta Lynch and Comey’s inner circle.

To abandon the Russian investigation at this time would be to play directly into Vladimir Putin’s hands and send the message to him and his henchmen that there are no consequences for their deadly serious attacks against our democracy. And yes, there are effective consequences available.

In summary, Paul Manafort is a pawn – but he is no sympathetic figure. He chose to cozy up and profit from consorting with one of our most formidable enemies and its surrogates. The charges against him were filed to secure his cooperation and testimony.

The beauty of our system is that our democratic process places ultimate power in the hands of ordinary Americans jurors who will be the final arbiters of not only the work of the special counsel but also the direction of the country. No such freedom exists in Vladimir Putin’s Russia.