Does the discovery of a briefcase prove that Harper Lee wrote a true-crime book?

A new book suggests that the novelist spent many years working on a manuscript called 'The Reverend'

Harper Lee.

In 2015, the journalist Casey Cep was sent to Alabama to report on the unexpected publication of a second Harper Lee novel, Go Set a Watchman. While she was there, however, Cep heard rumours about another project the author of To Kill a Mockingbird had been working on.

Lee had, it transpired, become fascinated with the case of Reverend William Maxwell, a preacher in Alexander City, Alabama, believed to have murdered six people, including two of his wives and one of his step-daughters. Maxwell was then shot three times and killed by the brother of his step-daughter during her funeral.

Lee, who died in 2016, spent many years researching the case for a true-crime book – and now Cep has tracked down a briefcase full of documents confirming that Lee had indeed made considerable progress on a manuscript often referred to as The Reverend.

In her recently published book on the subject, Furious Hours, Cep reveals that in 2017 she was contacted by the family of Tom Radney, Maxwell's attorney, to say that Lee's estate were returning a suitcase full of documents he had lent to the author in 1977.

In a piece for The Guardian, Cep writes: "The briefcase had been in her possession until her death; it was covered with dust, but brimming with legal files and Lee's other materials – everything from the catalogue of an occult bookstore where she bought voodoo books to the warranty for the tape recorder she used while reporting on the Maxwell case. I had spent years trying to reconstruct her work on The Reverend, and here were her files and photocopies, documents and research."

In 2015, Cep had revealed that a four-page chapter of The Reverend existed. The question is whether any more of the book is out there. Lee spent years holed up in a hotel in Alexander City trying to piece the story together. She admitted to being frustrated that her agent was only interested in "pure gore and autopsies", while her publisher just wanted a bestseller. "I want a clear conscience, in that I haven't defrauded the reader," Lee confided to her friend Gregory Peck.

In 1987, Lee sent a letter to another writer who was researching the Maxwell case. “I do believe that the Reverend Maxwell murdered at least five people, that his motive was greed, that he had an accomplice for two of the murders and an accessory for one,” she writes. “The person I believe to have been his accomplice/accessory is alive, well, and living not 150 miles from you […] I do not have enough hard facts about the actual crimes for a book-length account.”

Ultimately, Cep is unable to answer whether or not another Harper Lee book is out there somewhere. But in an interview with The New York Times, she said: "I think there's potential for her to have written the whole thing. People who lived around her on the Upper East Side heard the typewriter at all hours of the day and night."

Lee’s estate has been sealed since 2016.