The People vs. Thomas Gaffney, David March and Joseph Walsh is possibly the most important trial in this county since the legal fight over Baby T.

Remember that drama?

The case pitted Tina Olison, an African-American mother recovering from drug addiction, against Ald. Edward M. Burke (14th) and his wife, Anne Burke, now an Illinois Supreme Court justice.

Although the cases are very different, both divided the city along racial lines.

And in the same way the Baby T case sparked a grassroots movement pushing for family reunification, the Laquan McDonald police shooting has rallied black people around the important cause of police reform.

Although Olison lost her court battle, her case opened a lot of eyes to the injustice of putting the rights of white foster parents over the rights of a black biological mother seeking redemption.

As defense attorneys argued for a directed verdict in the cops’ conspiracy case on Tuesday, I became worried that justice might not be served. Fortunately, the judge denied the motion to end the case — though it’s still unclear whether the officers will be found guilty.

For one thing, the so-called “code of silence” isn’t a tangible thing. It is an understanding. I don’t expect any judge, interpreting the letter of the law, to break through the blue wall.

That’s something that police officers would have to do. The only officer willing to do that was a woman, Dora Fontaine, and she was allegedly called a “snitch” and a “rat.”

When it came down to it, McDonald did not have the same standing in the eyes of these police officers as their colleagues.

These three police officers walked into the courtroom with not just the presumption of innocence but also the presumption of privilege.

The Police Board is moving to fire four other officers tied to the McDonald shooting, though the city’s inspector general recommended 11 officers be fired because of their misconduct related to the investigation.

Frankly, the big question here is, “Where are the big fish?”

A conspiracy this widespread couldn’t have possibly been pulled off without the cooperation of higher-ups.

With video evidence showing McDonald walking away from the officers, it is hard to understand how a supervisor would approve a report saying the teen attacked the cops.

James McKay, an attorney for one of the three cops on trial, argues that the state is taking mistakes that were made in the McDonald police reports and wants to criminalize them.

But maybe that’s what needed to break the “code of silence.” After all, shouldn’t a citizen have an expectation that a police report will reflect what actually occurred?

A false police report could lead to an innocent person being taken into custody and being deprived of their civil rights.

Like Olison, McDonald seemed an unlikely candidate to bring about change. He was a ward of the state, had a documented history of disciplinary problems and was walking down a public street with a knife.

But the anger over that police-involved shooting was a turning point for the city.

After the release of video that showed the horrific shooting, young people from all parts of the city converged upon City Hall and publicly demanded the resignation of the mayor and the Cook County state’s attorney.

Because cameras were allowed in the courtroom, ordinary citizens could hear and decide for themselves the truth.

So far, the unprecedented decision has given us a look at the internal workings of the Chicago Police Department.

“I’m embarrassed by the lies and deceit shown throughout this saga of police overreach . . . The whole crux of this comes down to a lack of supervision and accountability,” a suburban police commander wrote to me.

The defense attorneys gave spirited arguments for directed verdicts by Associate Judge Domenica Stephenson.

“I have yet to meet the perfect police officer and I have yet to see the perfect police report, said Will Fahy, admitting that Gaffney “possibly made one mistake.”

For that mistake, Gaffney has been portrayed in the media as the “very face of police corruption,” as the “very face of everything that is wrong with the Chicago Police Department,” Fahy said.

When a police officer makes a mistake, it’s a huge deal because it could cost someone’s life.

But this trial is not about mistakes.

This trial is about lies.

Unraveling those lies is painful, but necessary.