Ellroy himself was traumatized as a boy by his party-animal mother's murder. (See his memoir My Dark Places for the whole sordid story.) So it is clear that Bud is partly autobiographical. But Exley, whose shiny reputation conceals a dark secret, and Vincennes, who goes showbiz with a vengeance, reflect parts of Ellroy, too.
L.A. Confidential holds enough plots for two or three books: the cops chase stolen gangland heroin through a landscape littered with not-always-innocent corpses while succumbing to sexy sirens who have been surgically resculpted to resemble movie stars; a vile developer--based (unfairly) on Walt Disney-- schemes to make big bucks off Moochie Mouse; and the cops compete with the crooks to see who can be more corrupt and violent. Ellroy's hardboiled prose is so compressed that some of his rat-a-tat paragraphs are hard to follow. You have to read with attention as intense as his—and that is very intense indeed. But he richly rewards the effort. He may not be as deep and literary as Chandler, but he belongs on the same top-level shelf.