Rust is a talented but troubled detective, dedicated to his work and renowned for his abilities, most notably his ability to get confessions from criminals. Rust is aloof, prefers living by himself, and he presumably hasn't been able to sustain a relationship for longer than a few years. Even though Rust prefers to stay out of other peoples business, he doesn't hesitate to show his disappointment and disgust towards Marty after he cheats on his wife, clearly disagreeing with his ways. 