In Walter Dean Myers's novel Monster, Kathy O'Brien is Steve's defense attorney; she handles his case and argues for his innocence, but she turns away from Steve Harmon at the end of the story.
Throughout the novel, Myers purposely makes Steve's involvement in the crime ambiguous as the audience struggles to grasp whether or not Steve actually participated in the crime. There are several scenes where Steve openly denies his involvement and states his innocence. However, there are also scenes where Steve wrestles with his conscience and doubts his innocence.
Given the information provided to the reader from Steve's journal passages and private interactions with Kathy O'Brien before taking the witness stand, the audience is led to believe that Steve initially agreed to participate in the crime and entered the drugstore with the intent of making sure the coast was clear. Upon entering the drugstore, Steve experienced a change of heart and walked a "moral tightrope" as he contemplated whether or not to give James King and Bobo Evans a signal when he left the store. Once Steve left the store, he made up his mind not to give James or Bobo the signal, in order to free himself from any responsibility. Steve lies on the witness stand by testifying that he never entered the store.
At the end of the trial, Steve Harmon is found not guilty. When he tries to hug Kathy O'Brien, she stiffens and turns away. Five months after the trial, Steve continues to experience identity issues and wonders what made Kathy O'Brien turn away from him after he was acquitted. Steve wonders if she saw him as a monster, which is what Sandra Petrocelli, the prosecuting attorney, labeled him at the beginning of the trial. One could surmise that Kathy O'Brien turned away from Steve Harmon because she believed that he was guilty and that his actions were repulsive.