How does the author characterize these two attorneys? The author What is he saying about defense attorneys in the legal system?

Kathy O'Brien is the public defender assigned to Steve. O'Brien is a "flat character"—she does not change over the course of the novel, and she lacks emotional depth. There is no information revealed about her personal life, her career, or her feelings about the trial. Rather, her actions demonstrate that she is a thorough and experienced pubic defender. She advises Steve Harmon to present himself in an approachable manner to the jury, and she even enlists a character witness to prove her defendant's innocence. Although she is cordial to Steve, O'Brien seems ambivalent about Steve's character. Her callous reaction to the result of the trial leads Steve to believe that O'Brien truly sees him as a "monster." I think the author is pointing out that systemic racism extends even to Steve's own attorney. Although she tries to do her job she has her own biases about young black men. I don't really think she believes in Steve or his innocence. Sandra Petrocelli is the prosecutor during Steve's case. She seems to think it quite natural that Steve is guilty. In many ways both lawyers share the same racial biases.