Who is Carolyn Polhemus from Presumed Innocent and what is their importance?

Carolyn Polhemus is the novel's murder victim. She is more than forty years old, but remains extraordinarily beautiful in a rather stereotypical way with a buxom and fit figure and a cascade of golden hair. Carolyn is a damaged person. She is intelligent and capable in her job as a deputy prosecuting attorney, but her ambitions to ascend in the hierarchy lead her toward initiating sexual relationships with several powerful men in the legal profession. She also gets involved in corrupt practices.