Harper Lee's Pulitzer Prize-winning “To Kill A Mockingbird” is a pillar of American literature, but many parts of Lee’s life have always been shrouded in mystery.

Writer Casey Cep uncovered one mystery while reporting on Lee’s 2015 novel, “Go Set A Watchman.” Cep visited Lee's Alabama hometown, where she discovered the author had once spent years working on a non-fiction account of another gripping legal case: the story of a local minister accused of killing five members of his family in the 1970s to collect insurance policies he signed them up for. Cep spent the next few years researching the case and Lee’s life. She tells the story of both in her new book, “Furious Hours: Murder, Fraud and the Last Trial of Harper Lee.”

Casey Cep joined Jim Braude.