Rusty is the protagonist and narrator of Presumed Innocent. He is almost 40 years old when the novel begins and is the chief deputy for the Kindle County prosecuting attorney. Rusty’s background in a working-class neighborhood, son to an abusive and distant father, shapes the features of both his personal and professional lives. Although Rusty is presented as a wholly credible and authoritative narrator, he is an unreliable narrator, as he withholds information to protect his wife, Barbara.

Rusty is both capable and loyal, running the prosecutor’s office while Raymond campaigns, in addition to his other duties. Rusty shows himself to be both observant and intelligent as he uses the time in trial for the charge of murder to assess the legal strategy and character of everyone involved in the trial.

Rusty’s character arc involves coming to terms with Carolyn’s death, his obsession with her, and finally, the fact that his wife Barbara killed her and potentially framed him. By the end of the novel, Rusty understands that his attraction to Carolyn was based in his instinctual understanding of her as someone with a similarly difficult background as himself.