If all crime novelists were as thoughtful and nuanced as James Lee Burke, we could finally put to rest those groundless prejudices against genre fiction. The marks of the thriller — violence, greed, unspeakable secrets — are always present in Burke’s stellar Dave Robicheaux series (as well as his fine Hackberry Holland series). But the books are works of dark art. At their unflinching best, they examine the cost of violence, even when it’s performed in the name of justice, and the haunted worlds inhabited by those resigned to limping through life with a blood-soaked conscience.

The specter of regret streams through Creole Belle, the 19th book in the series about Robicheaux, a New Iberia, La., homicide detective. Grim thoughts plague him: “My history is one of alcoholism, depression, violence, and bloodshed. For much of it I have enormous regret. For some of it I have no regret at all, and given the chance, I would commit the same deeds again without pause. ... ”

Robicheaux has good reason for wallowing in the uglier parts of his past: He almost made death’s acquaintance at the end of the previous book, The Glass Rainbow. He saw that ghostly paddleboat on the river with his dead parents beckoning and would have boarded it himself if not for a timely rescue by his brutish but loyal best friend, Clete Purcel.

That brush with mortality, though, has left Dave brooding — and a bit addled from morphine. He believes a local Cajun singer, Tee Jolie Melton, visited him in the hospital and left him an iPod onto which she loaded some of her favorite songs. But Tee Jolie has been missing for weeks. Her teenage sister is missing, too. And so Robicheaux sets off on a quest with Clete to find them, which leads him to the usual collection of malcontents, slackers and habitual criminals, the venial and the truly evil, including bickering members of a contentious, wealthy family; a bitter, racist former cop; crooked big businessmen; a death camp survivor whose story doesn’t quite ring true; and an abused, angry, mysterious young woman who may be an assassin — and Clete Purcell’s daughter.

As always, Louisiana comes fully alive, from the peaceful fog of the Bayou Teche to the manic streets of New Orleans. Ever present is the state’s Achilles heel: its deal with the demon — oil — that fueled its economy and ruined it, too.

Such contradictions trouble Robicheaux, but for him, “the greatest riddle involves the nature of evil. Is there indeed a diabolic force at work in our midst, a satanic figure with leathery wings and the breath of a carrion eater?” Even if there isn’t, Creole Belle makes a strong case that there’s more than enough bad in humankind to drag us all down.

Connie Ogle is The Miami Herald’s book editor.