If showmanship were everything, "Jade" would be one of the top 10 movies of the year. William Friedkin's direction is slick, Andrzej Bartkowiak's lensing is glowing and crisp, James Horner provides a tense score, Alex Tavoularis' art direction is luxurious, Kirk Francis' surround sound mix is excitingly crunchy, and an 11-minute car chase through San Francisco's Chinatown streets is a cinematic highlight that recalls Friedkin's original in "The French Connection." But this exceptional technique is in support of another thin and hollow story by Joe "Showgirls" Eszterhas. Here, assistant district attorney David Corelli ("Kiss of Death's" David Caruso) is out to solve the murder of an art dealer (Ron Ulstad) who was secretly photographing important men in bed with whores to blackmail them; one prostitute nicknamed Jade (Linda Fiorentino) in her more public life is Trina Gavin, a wealthy corporate psychologist and Corelli's ex-lover who's now married to Matt Gavin (Chazz Palminteri), a powerful and adulterous lawyer. In short, Trina seeks marital payback. If only the movie were as dramatically dimensional as it sounds. And it could have been, had it fleshed out the domestic story, had the haggard and bland Caruso his authoritative vitality of "Mad Dog and Glory," and had the audience a reason to care about the blackmail scheme and murders intended to silence Jade and the other callgirls. Palminteri is dynamic as the dominating Matt, whose marriage is based on his riches and charismatic command and who demands intercourse by his rules; but, after her muscle-flexing, star-making role in last year's "The Last Seduction," Fiorentino's double-life turn here is a distinct letdown. There are flashes of her trademark smoldering audacity but this is a weak part for a strong actress. Scene after scene illustrates Trina's loss of control: her hysterics over her husband's infidelities, her use for Matt's pleasure as she cries in closeup, her coming on to a haggard and bland David, her terror while chased by a hatchet-wielding psychopath, and her cringing before her husband when she learns his secret at the finale. Surely, this isn't the Fiorentino that her newfound legion of fans desire. Starring David Caruso, Linda Fiorentino and Chazz Palminteri. Directed by William Friedkin. Written by Joe Eszterhas. Produced by Robert Evans, Craig Baumgarten and Gary Adelson. A Paramount release. Thriller. Rated R for grisly afterviews of murder victims, violence, language and strong scenes of aberrant sexuality. Running time: 95 min.