Link Deas is expelled from the courtroom for speaking up for Tom Robinson without being under oath.

Much of the book concerns the trial of Tom Robinson, a black man who has been accused of rape by a nineteen year old white girl named Mayella Ewell.  Tom Robinson is being well defended by Atticus Finch, the father of the young narrator, Scout.

During the trial, the judge is Judge Taylor.  A trial is a formal affair.  No one is allowed to talk except under oath, because the people who are giving testimony are sworn to tell the truth.  The jury then knows that they are being honest and can be trusted.

When Atticus is questioning Tom Robinson, this is known as Tom’s testimony.  During Tom’s testimony, he is supposed to be the only one who is talking.  When Atticus finished asking Tom questions and Mr. Gilmer, the prosecutor, got up to cross-examine him, meaning ask him questions himself, this is when Mr. Link Deas, Tom Robinson’s boss, stood up and shouted out for the whole courtroom to hear.

"I just want the whole lot of you to know one thing right now.  That boy's worked for me eight years an' I ain't had a speck o'trouble outa him. Not a speck." (Ch. 19)

Judge Taylor was very angry, and had Link Deas expelled from the courtroom.  It was not because he did not want to hear what Link Deas had to say, or because he did not want the jury to hear what he had to say.  He just wanted to make sure that that Link Deas was under oath when he said it.  Because Link Deas was not under oath, his testimony was inadmissible and could have caused a mistrial, which is why Judge Taylor said, “I'll be damned if I'll listen to this case again!" (Ch. 19).  Atticus did not object, because he knew that Link Deas was out of line.  He seemed to think the incident was funny.

Why did Link Deas do what he did?  Mr. Deas was just a cotton farmer.  He did not know much about courtroom procedure.  However, he was there when the judge made his announcement in reaction to the request to clear the courtroom of women and children.

[You] will receive what you see and hear in silence or you will leave this courtroom, but you won't leave it until the whole boiling of you come before me on contempt charges … (Ch. 17)

So Link Deas knew that he was not supposed to shout out.  We can only assume that he was carried away with emotion, and wanted to help Tom Robinson.  A trial can be difficult to watch, especially when it seems as if it is lopsided.  It might have not looked to Link Deas like Tom Robinson was getting a fair trial.  In fact, with the racism in Maycomb, it really was not possible for him to get one.  Link Deas was just trying to swing things a little more in Tom’s favor.