WITH a fine pedigree in brutal, uncompromising crime dramas - Scarface, The Untouchables and Carlito's Way - director Brian De Palma would seem a perfect ringmaster for this handsome adaptation of James Ellroy's novel.

Unfortunately, Josh Friedman's script ties itself in knots trying to distil the book's dense plot, inspired by the real-life murder of a 40s Hollywood starlet, resulting in a baffling final 30 minutes saturated with hurried exposition and revelations.

The first hour stands The Black Dahlia in good stead, meticulously sketching the characters and laying the foundations for an intriguing romantic triangle.

Once the film broadens its scope, introducing characters from the upper echelons of wealth and power in Tinseltown, momentum and dramatic tension quickly dissipate.

One-timer boxers Lee Blanchard (Aaron Eckhart) and Bucky Bleichert (Josh Hartnett), nicknamed Fire and Ice in the ring, swap their gloves for police badges in a city controlled by crooked politicians and ruthless gangsters.

When B-list actress Betty Ann Short (Mia Kirshner), aka The Black Dahlia, is brutally slain, Blanchard and Bleichert investigate.

Lee becomes obsessed with the case at the expense of his relationship with girlfriend Kay (Scarlett Johansson), while Bucky strays into the web of vamp Madeleine Linscott (Hilary Swank), whose creepy and eccentric clan - father Emmett (John Kavanagh), loopy mother Ramona (Fiona Shaw) and younger sister Martha (Rachel Miner) - may be closely linked to the murder.

De Palma and director of photography Vilmos Zsigmond evoke the era with sepia-toned filters which capture the glamour and opulence of Dante Ferretti's magnificent production design, recreating the landmarks of a post-war Hollywood long forgotten.

While Eckhart blows Hartnett off the screen, Swank out-slinks Johansson thanks to some decent one-liners.

De Palma enlivens the testing two-hour running time with his dazzling, trademark flourishes including a breathtaking aerial tracking shot of the murder scene and a masterful showdown on a marble staircase.