It’s no secret that Harper Lee, one of America’s most famous and enigmatic writers, worked with Truman Capote on his book “In Cold Blood,” published in 1966. The story of a gruesome murder of a Kansas family, it was considered one of the first “non-fiction novels,” because it was based on a real-life crime, but highly embellished by the author. Lee’s help on her friend’s book proved vital, and she was said to have been struggling to write after the roaring success of “To Kill a Mockingbird” in 1960. Now journalist and first-time author Casey Cep reveals Lee’s efforts to write her own true-crime chronicle, one that, unlike Capote’s, would adhere to the facts. “Furious Hours: Murder, Fraud, and the Last Trial of Harper Lee” (Knopf) is the story of the true crime novel Harper Lee never wrote, and it’s fascinating.

In the 1970s, in Alexander City in rural Alabama, there was a black Reverend named Willie Maxwell who, besides preaching, quarried rock and employed a crew clearing timber for paper mills. He also, allegedly, began cutting a strip through his own family tree, losing a number of family members in a string of unsolved murders. “One by one, over a period of seven years,” Cep tells us, “six people close to the Reverend had died under circumstances that nearly everyone agreed were suspicious and some deemed supernatural.” With no tangible evidence, time after time, the not-so-good preacher avoided jail. Furthermore, he was the beneficiary of these unfortunates’ life insurance policies (most didn’t even know he had taken out a policy), and he was free to pocket thousands of dollars. It wasn’t long before locals began to gossip. Some suspected the he was using voodoo, while others believed he had an accomplice.

The only people, it appeared, who believed in Maxwell’s innocence were his lawyer, Tom Radney, a rare white Alabama liberal, and his second wife; his first wife was found strangled and beaten on the side of the road. Radney was a curious mix of honorable (in his opposition to racial discrimination) and devious (in his pursuit of money).

People lived in fear of the “Reverend Voodoo” for years, but then came the funeral of his final alleged victim, his own stepdaughter. That’s when Maxwell, who had “insisted that he was innocent – of his first wife’s murder, of his neighbor’s death, of his brother’s death, of his second wife’s death, of any crime whatsoever …” – was shot and killed by Robert Burns, a military veteran and a relative of the dead girl. Burns shot Maxwell in front of 300 witnesses and, unbelievably, Radney decided to represent Burns in court, too.

This all took place well over a decade after Lee, who was from Alabama, published “Mockingbird.” The introverted author was struggling with fame and, at the same time, she desperately wanted to write another equally revered book. Lee met Radney at the 1976 Democratic National Convention, and she was inspired by this opportunity to write a true crime novel of her own. Plus, she was renowned and influential enough to have anything she wanted turned into a book; Cep points out that “people joked that Harper & Row would have published Lee’s grocery list.”

Lee moved back to Alabama from New York, resolute to transform the narrative into an enthralling look at race and justice in the South. For a while she even took up residency in Alexander City. Unfortunately she suffered a paralyzing stroke before she was able to complete it.

“Furious Hours” is the attempt to put together a story that was all but forgotten. Cep’s portrayal of Lee remains true to what people know about the author during her lifetime – which is very little – while adding details about her youth, the agony of the long editing process of “Mockingbird,” and Lee’s wish to bring complex Southern characters to life. In the years following her debut novel, readers see Lee tortured by fame, taxes, booze and especially, the heavy expectations placed on her writing.

Lee wanted to discover the real story of Maxwell underneath the town’s voodoo theories and exaggerations, and like Lee, Cep loves facts. The research in this book seems extremely thorough. Alabama history is scattered about, and there’s almost an entire chapter devoted to the life insurance and fraud. Searching for friends and acquaintances of Lee’s, rummaging through press clippings and letters, and getting as near to the elusive novelist as she could, Cep has spliced together a Southern Gothic tale of murder along with the sad story of Lee’s literary career, to produce a tale that is captivating in its detail and deeply moving. It’s Cep’s characters, however, who really standout: a murderous and greedy man of the cloth, the humble black vigilante hero, the arrogant white lawyer who defended them both, and finally, an unassuming writer in search of the truth while fighting her own demons.

“Furious Hours” will please fans of Harper Lee, fans of Southern Gothic, and most of all, fans of true crime and literary lore. Cep has insightfully salvaged a gruesomely fascinating true-crime story and done Lee justice in a new and captivating portrait of this essential American writer.