EDITORIAL COOLEY STRIKES PROBE INTO L.A. CITY HALL CORRUPTION IS OVERDUE.

DISTRICT Attorney Steve Cooley, at long last, has shown a willingness to fulfill his promise to go after political corruption, influence-peddling and campaign finance scandal at Los Angeles City Hall.

By opening an inquiry into contracting practices at Los Angeles International Airport and winning indictments of 14 people linked to one of the region's biggest developers for conspiring to violate city campaign- finance laws, Cooley has sent a loud and clear message that he's serious about tackling corruption.

He's got his work cut out for him.

Bringing down the walls of the Kremlin was easier than penetrating the tight little world of L.A. politics. Cooley will need the help of all the good and decent people who have been afraid to speak up as well as the grand jury, which he used to win indictments against Casden Properties LLC senior vice president John Archibald and 13 of the firm's subcontractors.

Alan Casden is one of the nation's richest men and a major player in city politics, contributing heavily to City Hall politicians and their campaign against San Fernando Valley cityhood. Although many of his apartment and other projects in the city have faced major community opposition, City Hall has more often than not looked favorably on them.

Is there any connection? According to Cooley, Archibald, one of Casden's senior executives, was laundering political contributions - in order to skirt campaign fund-raising limits - through subcontractors, their families, friends and employees who were later reimbursed.

If he's right, then Cooley has identified a bona-fide case of dirty politics, surely not the only one. Cooley promises that this is ``the first step of an ongoing investigation into illegal campaign funding in the city of Los Angeles.''

An overdue one at that.

The open secret of L.A. city politics is that City Hall under Mayor James Hahn has come to look like the state Capitol under Gray Davis: You've got to pay to play. Efforts to sidestep campaign-finance laws are routine.

That's what makes the news of Archibald's indictment so startling. People try to funnel money into city campaigns all the time. Only now, the district attorney has opted to do something about it. In the past, such offenses resulted in little more than a slap on the wrist in the form of fines imposed by the Ethics Commission.

That's what makes the insiders and alleged culprits so incredulous. They can't believe the book is getting thrown at them, that they now face felony charges for what's widely considered standard operating procedure downtown.

``It's unbelievable,'' says L.A. attorney Dana Cole, representing one of the indicted subcontractors, Anthony R. Boozel of Granada Hills. ``My guy is alleged to have reimbursed a couple of friends to the tune of $3,000. He's being charged with felony conspiracy over $3,000. It's crazy.''

No, it's not crazy. It's justice, but, in an insane system where justice has long been absent, it may be hard for the insiders to comprehend. This case is about more than $3,000 or even a few high-profile campaigns - it's about the very way City Hall does business.

Cooley has taken on the mother of all investigations. If he sees it through, he'll be a hero and help bring a more democratic and honest government to Los Angeles. If he loses his nerve or fails in his mission, well, we'll let the voters be the judge.