Sooner or later, somebody was bound to get burned by the current TV fad of fictionalizing recent events. Today's smarting victim is NBC, which is airing "Undercover With the KKK" tonight at 9 -- one year after it was filmed.

The two-hour movie claims to tell the story of Gary Thomas Rowe Jr., who infiltrated the KKK for the FBI and did his job so thoroughly that he has now been indicted in the 1965 murder of civil-rights worker Viola Liuzzo. h

Birmingham police also suspect him in the 1963 church bombing that killed four black girls.

The indictment by an Alabama grand jury came after the film had been made. NBC lamely announces just as the movie lamely ends.

The sticky part, you see, is that Rowe has been presented as a sympathetic character, if not a hero, his life trashed by his double role, his friends murdered, his wife and kids gone, his neighbors hanging him in effigy.

And the FBI, represented by a weasel-faced cynic, have been shown up as double-dealers who urge him to seduce other Klan wives and join in the violence as much as necessary to reach the higher-ups.

There is also a mysterious hint that the FBI switched witnesses, placing their own black man in the death car with Liuzzo. This is never pursued, elaborated or explained in any way. It's just left like a hawser dangling over the side.

It must be embarrassing enough for NBC to have to announce that "the rature of Rowe's involvement is still unclear," but what can you expect if you insist on turning recent history into formula fiction?

"The characters are fictionalized," we are told, "but most of the events actually took place." Well, good. Which ones? Surely millions of Americans remember how Viola Liuzzo was gunned down in a car chase near Birmingham during the Freedom Riders era. Millions of us distinctly remember that it happened at night.

But now it has been shifted into broad daylight. No big thing, maybe. But if they changed that, what else did they change? What are we to make of the "composite" characters in the film? Was there really a lawman (nicely impersonated by the old pro, Slim Pickens) who was incinerated in his car? Was that other guy really murdered by rattlesnake?

Quite aside from the obvious risks of being overtaken by facts, I can't understand why NBC had to take a rather compelling true story and turn it into just another schlocky melodrama. As straight documentary -- with the real Rowe testifying from under his homemade hood in court and the new developments providing a climax -- it might have made a really arresting show.