In Monster by Walter Dean Myers, how does Steve represent his innocence in his notes?

Following an emotional visit from his father, Steve Harmon writes in his notes that he has never seen his father cry like that before. He begins to question himself by saying, "What did I do? What did I do?" (Myers 118). Steve then writes that anyone could simply walk around a drugstore, implying that he had no intention of checking to see if there were any police officers in the store. Steve then comments that he didn't do anything. He believes that everyone is confused because of the tragedy and emotional pain involved in the trial. Steve also mentions that he didn't kill Mr. Nesbitt or take any money from him. Steve's statements represent his innocence in the robbery and murder of Mr. Nesbitt. Steve admits to being in the store, but not to purposefully participating in the robbery and murder. Steve is even confused as to why he is on trial because he maintains that he did nothing wrong.