The first section of the book, a spellbinding true crime story, follows the Rev. Willie Maxwell, who allegedly killed five family members for insurance money in the 1970s. In a stranger-than-fiction twist, Maxwell himself was killed in 1977, shot at a funeral ceremony for one of his alleged victims by one of her grieving relatives.
But the other mystery proved even knottier. It involved reconstructing years of investigative work done by Harper Lee, who was fascinated by the Maxwell murders and worked on a true crime book about the case that she titled “The Reverend.” To this day, it remains unclear how much she wrote, why she stopped writing or whether she finished the book.
Cep first learned about the existence of “The Reverend” in 2015, when the literary world was stunned by the news that Lee was publishing another novel, titled “Go Set a Watchman.” When Cep went to Alabama to report on the circumstances surrounding the new book, she learned about another old Harper Lee project that hardly anyone was talking about — a rumored masterpiece of true crime that people close to Lee said rivaled Capote’s “In Cold Blood” (which Lee famously helped to research but received little credit for).
Cep may not have fully solved the cases, but she collected enough clues and vivid details to tell a captivating story. Below is an edited transcript of a recent interview with Cep about how she retraced Harper Lee’s steps.
Q: Which was the harder mystery to unravel, the story behind the alleged murders, or what happened to Harper Lee’s unfinished manuscript?
A: I’m not sure I solved either of them. But I hope I’ve given people all the evidence that I can for readers to draw their own conclusions about everything, from did the Reverend do it to how did he do it if he did it, and what did Harper Lee write, what didn’t she write or why couldn’t she write?
Q: What was the most challenging thing about taking Lee on as a subject?
A: There’s a tremendous amount of her inner life that remains enigmatic even to those who knew her best. She just was exceedingly private. It was not even just a public-facing privacy; it was even with people who knew her well, and I think in some of those core instances, she was inscrutable even to herself.
Q: The thing that was surprising to me in your book was how confident and how committed to the material she seemed to be. Why do you think she abandoned it, or never tried to publish it?
A: It is the big mystery of what became of Harper Lee, and this is one iteration of it. I think for a lot of readers, it’s unsatisfying because I don’t put my thumb on the scale. I think a different writer would have made a guess. It’s something I really think Harper Lee would appreciate about the book, the degree to which I tried to be scrupulous.
Q: But if you had to make a guess …
A: I am an optimist in general, and I’m an optimist about Harper Lee. She was an extraordinary writer and thinker, and there’s a way in which she had everything going for her with this book. Look, I did it, so of course she could have, and probably did, and there’s probably no one more excited to read whatever exists of “The Reverend” than me. I’m pretty sanguine. 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.
Q: And by your account, she gathered an incredible amount of material.
A: It was clear she had a mind for the investigation. She had all the pieces. She should be able to write it, and then we have to sit with the question of, what happened?
Q: Were you at all intimidated taking on a literary project that Lee had failed to complete?
A: I think “Mockingbird” is one of the most extraordinary novels in the English language, and the idea that the woman who wrote that couldn’t do it doesn’t bode well for the likes of Casey Cep. Imagine if you thought Harper Lee was going to tell your story, and then Casey Cep, this writer you’ve never heard of who’s never written a book, she’s not even from Alabama, I think for some of these people it was like, “We get you? We were supposed to get Harper Lee and we get you?”
I felt like there was one thing I could do which she was never going to do, which was talk about her. It’s the story behind the story. She would never have included herself.
Q: There’s an amazing moment near the end of the book when you get this trove of documents about the Maxwell case that Maxwell’s lawyer, Tom Radney, had given to Harper Lee. What were some other breakthrough moments in your reporting?
A: I had been told the court reporter from the murder trials was dead. At some point I realized I didn’t know that for sure, and I was looking for women by that name, and it turned out she was alive and well. I go knock on the door, we get to talking about the Maxwell case and a couple of minutes into that conversation she goes, “Gosh, I haven’t talked about this since I talked to Harper Lee.”
Q: Were there any questions that you tried really hard to answer that you were unable to crack?
A: Harper Lee smoked cigarettes like a chimney. You will notice that I do not name the brand of cigarettes she smoked in the book. She’s shown holding them in some photographs but the pack is never visible. As much as I want to tell you I think they were Chesterfields, I could not say that with certainty. So I just tell you she smoked.
Q: One gets the sense that you have a real affection for Harper Lee and yet you expose her demons, her heavy drinking, her insecurities, her disdain for her hometown. Was it difficult to draw out sources on those aspects of her life?
A: People were happy to finally get to talk about it, trusting that it would be represented in a responsible way and not a sensational way. A lot of people felt like they didn’t want to embarrass her in her lifetime, but they wanted to let the world know that she struggled.
Q: What do you think Harper Lee would have made of your effort to finish the story she never told?
A: People ask me sometimes, do I think she would like the book? I respect her enough to say, probably not. I don’t think she would have approved of someone looking so seriously at her life. And yet I think that she valued the truth a great deal and would have admired the extent to which this is a book that tried to tell the truth.
This article originally appeared in The New York Times.