How Much Fact Does It Take to Make Reality-Based Drama? : Movies: The line between docu- and -drama is uncertain. And Bruno Barreto’s ‘A Show of Force’ straddles it with unsettling difficulty.

There is no gloom, frustration and rage to match a filmmaker’s whose film has apparently been prejudged by its distributor as a commercial bust and is effectively abandoned at birth, before audiences have had a chance to vote for themselves.

So it seemed with Bruno Barreto’s “A Show of Force.” It was not quite abandoned by Paramount. The film opened in about a dozen cities, though with minimal advertising and promotion and, here at least, with press screenings withheld until the day before opening (a telltale sign that the distributor would rather risk the critics’ wrath than their reviews).

On the face of it, it sounded like a curious dismissal. Barreto made a very successful and critically acclaimed sexy comedy, “Dona Flor and Her Two Husbands.” “A Show of Force” stars Amy Irving, a marquee name, with Robert Duvall, another marquee name, in a large supporting role. (The film is a family affair, the star having recently given birth to Barreto’s child.)

More than that, “A Show of Force” manifestly aimed for the kind of political electricity Costa-Gavras achieved so memorably in “Z.” The setting is Puerto Rico, not Greece, but the basic situation is also from history.

But history never lends itself to the movies without the pushing, shoving, cutting and filling of poetic license. The question always is, how much manipulating did it take to make history fit the demands of drama?

The murders of three civil rights workers that were the basis of “Mississippi Burning” were not at issue. But a good deal of the surrounding text was, even though the film’s capturing of the more general atmosphere of the times was convincing enough.

The larger truth of Ron Kovic’s conversion from patriotic Marine to no less patriotic anti-war protester is not in question, but it has become clear that certain characters and events are fictional, including the brutality by Syracuse police in a riot scene.

What is troubling in all of television’s docudramas and all historical films is just where the imaginary hyphen divides docu- and -drama, where invention begins, and ends. The viewers, unless they were there or are well-versed scholars, can’t really know. Unless the film is immensely skillful, the skeptical watcher may reject the re-created fact along with the new fiction.

The disclaimer at the end of “A Show of Force” says that the film was inspired by real events. This was the killing by police of two students who were making a badly bungled attempt in 1978 to seize a Puerto Rican radio station to broadcast messages in favor of independence (rather than statehood or a continued commonwealth status).

The odor of frame-up and police corruption still clings to the incident, and the Legislature is still investigating. The disclaimer then adds that some events and characters are fictitious, specifically including the rogue FBI man who is the principal villain of the story. In the film, the FBI man (played with perfect menace by Kevin Spacey) acknowledges that he’s a loner, a right-wing zealot acting on his own, which, at least for the purposes of the film, gets the bureau off the hook.

“A Show of Force” does a good job of creating a situation where, as in “Z,” everyone appears to be in on the conspiracy and no one, in or out of uniform, will protect the innocent and pursue the guilty. No one except, for dramatic purposes, Irving as a fearless newscaster whose dead husband was himself a fighter for independence and a young prosecutor who feels that the processes of law are armor enough. Irving and Andy Garcia are fine in the roles, and, at its best, “A Show of Force” will evoke the paranoia in a saint.

But if the FBI man is a total fiction, what is the film really saying? The politics of Puerto Rico haven’t been clarified but muddled. The melodrama, and not least a marvelously improbable and unconvincing denouement, have undercut the truer tensions and the harder if less vivid revelations that the script by Evan Jones had initially seemed to be trying for.

As Michael Wilmington pointed out in his review, there are holes in the plot and credibility gaps a pair of oxen could stroll through. It is clear but not sharply enough said that Duvall as the TV station manager is, if not part of the conspiracy, a silent and willing backer of it. He is a loose end left hanging.

The final frustration is that the politics of Puerto Rico seem well worth talking about, although ideally in a movie that needed less of the trappings of the traditional tidy thriller. The docu- is fine, the -drama is wanting.

In this case the distributor may have been right in guessing that “A Show of Force” would not be a big box-office winner but might do better in the cassette market later. But as I write, it is still hanging in at the Mann Plaza in Westwood and, flaws and all, it is more interesting (that damning word) than many a less ambitious romp available for our delectation.