Chicago long ago rescued its film and TV production industry from years in the cinematic doldrums, but not without criminal elements creeping in.

On Tuesday, onetime labor leader John T. Coli pleaded guilty in federal court to taking part in a scheme to extort $325,000 from Cinespace Chicago Film Studios. Coli, a politically connected former Teamsters boss, had demanded quarterly extortion payments, in cash, and had threatened to shut down the studio in North Lawndale if the money stopped coming.

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With Coli’s guilty plea, the curtain went up on a seamy underside of the film industry in Chicago, featuring a kind of petty corruption — common to the entertainment world — that our city and state can ill afford.

The film industry has become a vital part of our local economy. And the same pressures will come to bear — and the same vigilance will be necessary — when a new casino comes to Chicago.

Caught on federal wiretaps, Coli sounded like a character straight out of a Martin Scorsese movie.

“We’ll shut it down tomorrow. We’ll shut it down within an hour,” Coli is recorded saying when told the extortion payments might be stopped. “I will f------ have a picket line up here and everything will stop.”

Coli also suggested that the head of Cinespace, Alexander S. Pissios, get rid of the studio’s chief financial officer because “you can’t have a f------ rat in a wood pile. You can’t have a whistleblower here.”

In a later conversation, when Pissios assured Coli that the payoffs would continue, the Teamster leader’s unapologetic answer was: “Perfect.”

This kind of expensive extortion is an excellent way to kill an industry.

Last year alone, according to the Illinois Film Office, 332 television, film, digital and commercial advertising projects were produced in the state, generating an estimated $473.9 million in spending. The film industry here has created thousands of jobs in a wide variety of fields, from specialists in lighting and audio, to caterers and on-screen talent. It has given a boost, as well, to film programs at DePaul University, Northwestern University and Columbia College.

A crook like Coli, as well as others who may still be caught up in this federal probe, can’t be allowed to mess with that.

We feel like we’re only about halfway through a four-star movie, and we’re waiting to see what happens next. Coli has agreed to cooperate with investigators as part of his plea deal, so the script is likely still being written.

Of interest to us is a diamond engagement ring that a former campaign manager for Gov. Pat Quinn bought for his fiance, Quinn’s press secretary. Pissios told the FBI that he helped pay for the ring — at the suggestion of a lobbyist close to Coli, the Sun-Times reported earlier this year.

A subpoena also was issued in February for the personnel file and other records of state Sen. Thomas Cullerton, D-Villa Park, who has worked for the Teamsters and who is chairman of the Senate’s Committee on Labor.

Early in the 20th century, Chicago was the nation’s leading film producer. Charlie Chaplin got his start in film here. But by mid-century production studios had moved away. Former Mayor Richard J. Daley actually threw up roadblocks to Hollywood filmmakers, concerned they would depict the city negatively.

Chicago’s film industry has rebounded largely because of a 30% state tax credit on all production costs. Hit TV shows such as “Chicago Fire” and “Empire” now are produced here.

But now it appears federal prosecutors are investigating the $420 million in state tax credits given to the industry over a decade’s time — and any favors that might have been done in return. A spokesperson told the Chicago Sun-Times Editorial Board the Illinois Film Office has had no contact with federal investigators.

Chicago is finally a long way from the days when movies supposedly filmed here, such as ‘’My Big Fat Greek Wedding’’ and ‘’Chicago,’’ actually were filmed in Toronto.

Let’s keep it going. But let’s clean up things behind the scenes, making sure the money taxpayers are spending to lure productions here is being spent wisely.

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