Most people are probably going to view "In the Belly of the Beast: Letters From Prison" as a violent denunciation of the subhuman conditions of our penal institutions. It is that, of course, but it is something more.

Buried in this savage account of the life of convicted murderer Jack Henry Abbott is the cry of a wounded man, who is trying to come to some understanding of himself. Flickering dimly in his battered soul, like a candle in a tornado, is a primeval sense of responsibility. It is perverted almost beyond recognition by a lifetime in prison, but it nonetheless there. And it prompts him to ask the questions that have always plagued mankind: "Why am I?" "Do I exist?" "Does the world exist?" "Is there a God?" "Am I the Devil?"

With "In the Belly of the Beast," which opened a three-week run Friday night, the Kennedy Center's American National Theater has accomplished a double baptism. The production, which hails from Chicago's Wisdom Bridge Theatre, is the first in what ANT intends to be a continuing series showcasing significant regional theater work. It is also the first to play in what was once a musical theater lab. That cavernous facility on the top floor has now been redubbed the Free Theater, which means just what it says: no admission will be charged for the 200 bleacher seats.

The prospect of free theater alone is an intoxicating one, but when it proves as potent as "In the Belly of the Beast," it has to be considered a turning point in the Kennedy Center's history. ANT is not giving away a flossy little puppet show or the staged reading of a work-in-progress, more often than not a euphemism for somebody's first draft. It is throwing open the doors on the real thing -- a raw, abrasive production that hurls itself at an audience, jabs at its conscience and challenges its equanimity.

Thrust from the womb into a series of brutal state-run foster homes, Abbott first went to prison at the age of 12. He has been there ever since -- with the exception of a six-week parole in 1981 that came to an abrupt end when he killed a New York bartender in a scuffle over the use of a restaurant toilet. A series of letters from behind bars, written to novelist Norman Mailer and published under the title "In the Belly of the Beast," helped bring about his momentary freedom. Ironically, Abbott was on the verge of being proclaimed a major literary celebrity when he gave society reason to call him a murderer all over again.

Wisdom Bridge's theatrical piece (it somehow seems all too untidy to be called a play) has been fashioned from those letters and also from the transcripts of his subsequent trial. It is high-voltage material and it occasions a performance of furious intensity from William L. Petersen. As Abbott, the actor knows no surcease of rage and at one particularly fierce moment bangs his head repeatedly against a metal filing cabinet. On those rare occasions when his body relaxes, his eyes -- quick, glimmering, wary -- keep up the ferret's watch.

Although much of the script consists of monologues, virtually spat off the stage, two other actors, Tim Halligan and Peter Aylward, are on hand to play the various guards, prosecutors and even passing bimbos who thread through Abbott's cursed destiny. The production employs the strategies and ploys of Story Theatre: the actors talk in both the first and third person; within the general confines of Robert Falls' set -- a grim, greenish locale that functions as all the way stations of incarceration -- time and place are constantly shifting. A mattress, spilling its stuffing, serves as an eviscerated body. Where there are scenes, they are fragmentary, sharp splinters of reality in the huge, continuing torment of Abbott's mind.

Falls, who also directed the piece, lighting designer Michael S. Philippi and sound designer Jim Kusyk have conjured a palpable nightmare out of reverberating echoes, blinding lights and suffocating shadows. When Abbott, in fact, describes the unholy agonies of solitary confinement, the theater itself is plunged into claustrophobic darkness. In the strip cell, no more than a stinking toilet, Abbott cries out in a voice parched with thirst and thick with nausea for something to drink. Slowly, implacably, a dimly lit guard on the far side of the stage pours a glass of water on the floor.

The production is filled with such graphic illustrations of the sadism and ignominy of prison life. But while "In the Belly of the Beast" makes an implicit plea for reform, its primary concerns go far deeper. What, it is asking, happens to a man who has been deprived of even the most trivial of socializing influences? Who grew up without family and learns of his mother's death only when a guard bellows the news through the grate in his cell door? Who, for nearly two decades, has had no personal contact with another human being, except in violence? Whose only knowledge of intimacy is feeling another man's heart throbbing on the tip of his stiletto?

Abbott knows he is a freak -- a grown man with a grown man's intellect, perhaps, but with a boy's emotions. He also knows that his vision has been distorted by a life in prison and that he misconstrues the most ordinary gestures and situations of civilization. Why shouldn't he? "I've been denied the society of others," he says. "It's as simple as that." Or as complex.

His anger toward a world that has thus crippled him remains untamed. But still, he wants to see clear, figure out his freakishness, come to some awareness of self. Like all the heroes of drama from Oedipus to Willy Loman, he is looking for the light. This production doesn't always keep that aspiration in focus. In fact, it sometimes gets lost in the horrible sensationalism of things. Falls and Petersen have a tendency go for slam-bang urgency at the expense of Abbott's inner disquiet, which may be even more troubling.

Mangled as Abbott's conscience is, you see, it has not gone dead. He recognizes "something like a child deep inside us all that suffers." That "something" is what lends "In the Belly of the Beast" a touch of grandeur amid so much misery.

In the Belly of the Beast: Letters From Prison. Adapted from the book by Jack Henry Abbott. Direction and scenery by Robert Falls; lighting, Michael S. Philippi; sound, Jim Kusyk. With William L. Petersen, Tim Halligan, Peter Aylward. At the Free Theater through June 29.