In Harper Lee's novel, To Kill a Mockingbird, in Chapter Sixteen, Mr. Gilmer, the prosecuting attorney tries to make two points during his cross-examination of Tom Robinson.
The first thing he brings up is the fact that Tom was arrested for fighting with another man. Gilmer is not interested that it was considered a "misdemeanor;" he simply wants to establish that Tom is violent, and capable of violence—inferring his capacity to visit violence upon Mayella Ewell.
I believe the second thing he his trying to establish is the reason Tom was on the Ewell property: that it was his choice and he was pursuing Mayella, rather than the other way around. In disputing Mayella's version of the incident, Gilmer tries to get Tom to admit that he is calling Mayella a liar, but Tom simply says she was "confused in her mind." Gilmer tries to take Tom's presence at the Ewell home on various occasions as proof of his pursuit of Mayella, rather than helping her with chores as he has testified. Gilmer asks:
Had your eye on her a long time, hadn't you, boy?
Tom repeatedly denies that he did anything inappropriate, but Gilmer is only interested in twisting the truth.
The solicitor, or prosecutor, in the trial of Tom Robinson in Harper Lee's To Kill a Mockingbird, Mr. Gilmer, is introduced to the reader in Chapter 16. Scout, the novel's young narrator and main protagonist, describes Gilmer as a middle-aged, somewhat unattractive man with some kind of eye condition that makes it appear that he is looking in one direction when he is actually looking in another. As the trial commences and the first witnesses are called to testify, Scout continues to describe the scenery and the developments with a studied neutrality born of prior experiences observing her father in court. As the young girl notes after the solicitor begins to question Bob Ewell, the virulently racist father of the victim, "Mr. Gilmer was doing his job, as Atticus was doing his. Besides, Mr. Ewell was Mr. Gilmer’s witness, and he had no business being rude to him of all people."
Chapter 19 of To Kill a Mockingbird begins with Atticus's calling for the defendant in the rape case, Tom Robinson, to take the witness stand in his own defense. Atticus knows that Tom was physically incapable of committing the crime to which he was accused, but he is equally aware that, in the American South of the 1930s, when a black man is accused of raping a white woman, facts do not really matter. Tom's conviction is a forgone conclusion. Atticus, though, knows that he is legally, and morally obligated to proceed without regard for the racial biases that he knows have tainted the case and that will ensure a miscarriage of justice.
Having established in his questing of Tom that the defendant is a good and decent man who was also physically incapable of beating and raping Mayella Ewell, Mr. Gilmer now knows that he has to discredit Tom's testimony, and he does this, first and foremost, by dehumanizing the accused. Note, for instance, the following exchange as the solicitor cross-examines the witness:
“You were given thirty days once for disorderly conduct, Robinson?” asked Mr. Gilmer.
“What’d the nigger look like when you got through with him?” “He beat me, Mr. Gilmer.”
“Yes, but you were convicted, weren’t you?”
Atticus raised his head. “It was a misdemeanor and it’s in the record, Judge.” I thought he sounded tired.
Gilmer is legally obligated to prosecute the accused--although, realistically, he could have refused to prosecute on the obvious grounds of a lack of physical evidence--and, in so doing, he does what lawyers for both sides of cases do everyday: seek to discredit the other side's witnesses. He does first by raising the issue of Tom's previous encounter with the law: a case of disorderly conduct for which Tom was convicted. Because the case involved violence, Mr. Gilmer has now suggested for the jury's benefit that this crippled man has engaged in violence in the past, so could have done so again. It is up to Atticus, however, to set the record straight, that the crime was a misdemeanor. The damage, however, is done. The fact of a previous criminal record, involving violence, has now been established, and Tom's disability is no longer relevant to an already deeply-biased jury.
The other point that Gilmer succeeds in making is the more obvious one of Tom's socially and legally inferior status in Maycomb County. Tom, of course, is an African American, a dubious distinction in the Deep South. By both addressing Tom deliberately discourteously as "Robinson," rather than as "Tom" or as "Mr. Robinson," and by applying the "n-word" in the context of Tom's previous encounter with the criminal justice system, Gilmer is further emphasizing the defendant's race--an obvious tactic with all-white jury. In short, while Scout is correct in pointing out that Mr. Gilmer is only doing his job, her narration just as assuredly emphasizes the morally repugnant manner in which this county official performs his duties.