Rusty Sabich, the protagonist of Scott Turow's bestselling debut, Presumed Innocent (1987), returns in Innocent.

How long had you been planning this book?

For most of the two decades since Presumed Innocent, I was not thinking about a sequel. About five years ago, I suddenly became more open to the idea. I had noticed a Post-It that was on my desk that read “a man is sitting on a bed in which the dead body of a woman lies,” and realized that Rusty Sabich was that man. I had to decide who the woman was, and pretty quickly decided it was his wife, Barbara. I was really afraid of self-imitation. I was proud of Presumed Innocent and did not want to diminish it. At the end of the day, it was really the strength of the idea that overpowered my doubts.

How early on did you know who was responsible for Barbara's death?

I wrote for a good two years without knowing the answer. When the ending came to me, I was really pleased because it was both surprising in the context of the novel and resonated with the previous book; it also really deepens the reader's understanding of both Rusty and Barbara.

Readers of the first book may wonder about the more positive portrayal of prosecutor Tommy Molto.

Presumed Innocent presented Molto as a wretched little zealot. He surprised me here. I've been lucky that in the course of my work as a novelist there's always been a character who runs away with the book. When I wrote the first draft of the first chapter featuring Molto, the voice in it and the sense of his character was so strong that I just came back to it again and again. With Molto, I use a third-person past tense, as opposed to the first-person present tense voice I use for Rusty, and that helps create a distinct sense of two guys who see the world very differently.

How is Rusty different in this book?

He displays worse judgment overall; he's older and more desperate. He traces his own mistakes back to the trauma of his first trial for murder. As a criminal defense lawyer, I was always deeply impressed by the toll taken on my clients who've been lucky enough to walk away. He's clearly making the same mistakes all over again, something that I've seen my friends, and even myself, do. This is a guy reaching for something that he knows at the end of the day will not fulfill the hopes he has for it.