That's an understatement. There can be few works more disturbing than the crime novels that make up the LA Quartet, set in Los Angeles between 1946 and 1958, and the Underworld USA trilogy, which traces wider events from 1958 to 1972, taking in the assassinations of JFK, Bobby Kennedy and Martin Luther King. Bodies pile up. Race divides. Brutality and cold calculation rule. It's a more truthful account of American history, Ellroy claims, than the "official version and the Marxist revisionist version", both of which, he says, "should be judged as equally fallacious".
His new novel, Perfidia, is the first book in a planned new LA Quartet, which returns to the lives of some of his best-known characters, such as Kay Lake from The Black Dahlia, and Sergeant Dudley Smith, in the years between Pearl Harbour and V-J Day. It had its roots, Ellroy says, in a "synaptic flash" that he had in the winter of 1981. "I saw quite vividly scenes that will actually appear in the second book, of buses and humpbacked 1940 vintage cars and handcuffed Japanese; snow-capped mountains. These folks are being rounded up and driven to the Manzanar internment camp [at the foot of the Sierra Nevada]."
It opens with detectives called to the blood-soaked Los Angeles home of a Japanese family, who have apparently killed themselves in an act of hara-kiri. Among the cops is a gifted Japanese chemist, Hideo Ashida. The deaths are the prelude to an ever-darkening tale of a fear-driven city in the grip of a reckless wartime energy. "Frankly, it was a hell of a place to be," says Ellroy.
Setting his characters on course to a known future was an epic task. To render it seamless with the existing books, Ellroy spent three months re-reading all his relevant novels, mapping the lives of his characters in detail. The plot-planning alone ran to 700 pages.
He comes clean about one of the book's main protagonists. "William H. Parker is the darkest, the truest, the most redemptive self-portrait I've ever written. He's got my proletarianism, my Christian fervour, my piety, my profligacy, my restlessness, my need to control my environment, my extreme ambition, my fear, my alcoholism, all of it."
Parker also has an obsession with a red-haired woman he barely knows. I ask Ellroy if she bears any relationship to his own mother. "Yes she does," he says sadly, "my mother's the quintessential tall redhead to me."
Parker's alcoholism belongs to Ellroy's past. He no longer drinks. Parker is also a real-life figure. He was chief of police in Los Angeles from 1950 to 1966. In Perfidia, Parker is making his way up the ranks.
It's pure Ellroy: the writer who tells me that in his late teens and early 20s he was "breaking into houses to sniff girls' and women's undergarments, steal money out of wallets and purses, and pop pills out of medicine cabinets", grafting a self on to the man he regards as "the greatest American policeman of the 20th century". In Ellroy, fact combines with fiction in startling ways.
At 66, the novelist has begun to view his early years from a new perspective. "I [broke into homes] about 20 times. I never stayed inside very long. Let's say, arbitrarily, I stayed inside for half an hour a pop. That's 10 hours, out of my lifetime. I recall runs of days where I spent 10 hours a day in public libraries reading books. But that's not as punchy."
Reading shielded him from the world at large, he says. "I only wanted to be a novelist because I loved reading novels more than anything."
Ellroy's street-level existence stretched over 12 years, and included periods of "going through the LA county jail system", before he turned his life around, got a job as a golf caddie and wrote his first detective novel, Brown's Requiem (1981).
He has published two volumes of autobiography. My Dark Places (1996), his account of the investigation he conducted with LA Detective Bill Stoner into his mother's unsolved murder, is one of the most unflinching memoirs ever written. "I think that it was my concerted effort to come to know my mother. I realised that it was extremely unlikely we'd find the killer, and that I had to keep notes of my mental state, and my emerging relationship with this woman to give the book credibility because it's a nodunit and we're never going to know." It put him in a "state of grace", he says, and allowed him to remember her with greater affection.
The Hilliker Curse (2001) revealed how he believed he had caused her death. After the break-up of his parents' marriage and his mother's relocation to El Monte and a new life that involved heavy drinking and a succession of men, Jean had asked the young James to choose between his mother and father. When he told her that he would rather live with his father, she hit him and he fell, cutting his mouth on a glass coffee table. He called her a whore and a drunk, and she hit him again. He wished her dead at that moment and three months later she was. He assumed responsibility for her death.
My Dark Places also detailed his own life after the murder; the squalid poverty he settled into with his father, a Hollywood "hanger-on", who had once been business manager to Rita Hayworth. He bought his young son crime novels, but Ellroy swapped The Hardy Boys for the brutal charms of Mickey Spillane and true-crime stories. He became obsessed by the 1947 Black Dahlia murder, in which 22-year-old Elizabeth Short was killed, cut into pieces and left in a vacant LA lot, a crime that would later resurface as the entry point to his mature fiction.
Short provides the most striking element of Perfidia. Ellroy has introduced the 17-year-old Boston native as the love-child of his fictional - and deadly - Irish cop Dudley Smith. He was gripped, he says, by the idea of showing Beth Short "breathlessly alive, sweet natured, presciently intelligent ... just the idea that there is this wrenching love between this bad man and this young girl who will go on to have her life snuffed out".
Ellroy is unconcerned that some might find this stretching credibility. "People are connected in ways that we can't imagine. I'm sure you know people that I know. We're out there, we're one soul."
It's not the only collision between fact and fiction in Perfidia, which also includes an affair between Smith and Bette Davis. Like much of the scurrilous celebrity innuendo that finds its way into Ellroy's novels, it's not a flattering portrait of the film star. I ask him if he reads the memoirs of all the real-life people he depicts.
"No," he says. But "Bette Davis wrote a self-serving memoir called The Lonely Life. It oozes isolation and self-pity. It oozes entitlement. It oozes the sense of 'all these men are weaker than I'. She and [husband] Gary Merrill adopted a retarded girl and - she never says this but it's there - the girl was unfetching, she was difficult, she was prone to moods, and they put her in an institution and brought her out once a year for a period of days for Christmas time. It made my skin crawl. And you know what, I thought, 'Ellroy, that's all you need to know'."
