Former housing secretary Henry Cisneros, one of our finest public servants, goes on trial here this month for undercounting his girlfriends and fibbing about how much one of them cost.

It's a silly charge, unworthy of the federal government's attention.

The leading witness is a proven liar. The prosecution admits the tapes she made have been doctored. The obsessive "independent counsel," David Barrett, is not an independent in the normal sense of the word but a failed Republican office-seeker.

In a rational world, Cisneros would be given a pass. But FBI Director Louis Freeh insisted on prosecuting him, government sources say, to make the point that it is a serious crime to lie to the FBI, even on trivial subjects.

So it is with some irony that we discover that once again, Freeh's own FBI has been caught lying. After six years of denials, the agency has admitted that incendiary tear-gas canisters were used just before the tragic assault on the Branch Davidian compound in Waco, Tex., on April 19, 1993.

An FBI lie about Waco should be no surprise. The final attack on the compound began with a lie. Agents told newly installed Attorney General Janet Reno that children were being sexually abused inside. They had no evidence to back this up, but for Reno, who oversaw child-sex cases in Miami, it was enough to go over the top.

Plus, Reno was told that the FBI's hostage rescue team would be unable to continue its siege much longer. And the FBI's psychiatrists predicted that David Koresh and his cult would not commit suicide if federal agents moved in.

On the basis of the FBI's false warnings and false assurances, Reno ordered the attack in which some 80 people, including Koresh, were killed.

Of all the lies, the one about the tear gas is probably the most trivial. The two canisters were fired at a bunker about 75 yards from the inhabited main building and played no role in igniting the fires that killed the Branch Davidians.

This is an embarrassment, not a criminal plot. The conspiracy theorists who inhabit the Internet and talk radio are having a field day, even though the basic truth about Waco -- that Koresh and his followers set the fires in a combination of mass murder and mass suicide -- remains valid. Reno is on the hook only because she repeated the FBI's false assertion that it had not used incendiary devices.

The FBI deserves to squirm over this one. An ordinary citizen who gives a false statement to any government investigator faces a possible five-year prison sentence, no matter how trivial the lie. FBI agents attached to independent counsel Kenneth Starr threatened Monica Lewinsky with 27 years in prison -- in itself a lie -- when they picked her up on suspicion of lying in a federal civil lawsuit.

Surely an FBI official who lies to the attorney general ought to face the same kind of penalty.

And yet, common sense tells you, it's not worth it. The agents involved didn't cover up any material wrongdoing; the use of the tear gas didn't cause the Waco tragedy.

Common sense, however, isn't the hallmark of the congressional committees that will turn this case into a circus. And common sense didn't guide the FBI, which forced the prosecution of Henry Cisneros. No, Freeh doesn't need to be brought to justice, but he deserves a little poetic justice.

(C)1999, New York Daily News