A witness is defined as anyone who can present evidence in a case ("Witness," West's Encyclopedia of American Law, 2nd. ed.). In Harper Lee's To Kill a Mockingbird, Tom Robinson's trial was extremely unusual due to lack of evidence and the fact that only two out of four people who testified at the trial can genuinely be considered witnesses, though the plaintiff and the defendant of a case certainly can testify as witnesses.
In the case, Mayella Ewell is considered the plaintiff, the person who is accusing another of wrongdoing. Tom Robinson is considered the defendant, the person who is being accused of a crime or offense and is denying involvement (West's Encyclopedia of American Law, 2nd. ed.). Both the plaintiff and the defendant certainly can serve as witnesses by taking the witness stand to state their own testimonies of what occurred; however, their testimonies are given less weight than the testimonies of actual witnesses, and the burden of proof always rests on the plaintiff. In other words, it would have been Mayella's responsibility to prove the crime actually took place, and her own testimony alone would not serve as proof. In the case, both Mayella and Robinson served as witnesses by taking the stand. While it is more common for plaintiffs to take the witness stand, it is less common for defendants to take the witness stand, and defendants are Constitutionally protected from having to do so. Often, a defense lawyer will not call a defendant to the witness stand should he/she say something that damages the case under cross-examination by the prosecuting attorney. However, in this case, Atticus felt he had no witness to call other than Robinson himself.
One key witness in the trial is Sheriff Heck Tate, who testifies having seen Mayella looking very beaten up. Sheriff Tate gives two crucial statements that give Atticus grounds to motion to dismiss the case, a motion he sadly does not make. Sheriff's first crucial statement is that a doctor was not summoned to examine Mayella on the evening in question. Sheriff Tate states the following to Atticus in defense of having not called a doctor:
It wasn't necessary, Mr. Finch. She was mighty banged up. Something sho' happened, it was obvious. (Ch. 16)
However, Mayella isn't just accusing Robinson of having abused her; she is accusing him of having raped her, and based on the principle corpus delicti, meaning body of the crime, it is illegal to try a defendant without concrete evidence that the crime actually took place. A doctor's testimony would be essential for Mayella's proof, and without such proof, the case could have legally been dismissed. The second crucial statement Sheriff Tate makes is that Mayella was bruised in her right eye, which could have only been accomplished by a left-handed person facing her. Since Robinson is crippled in his left arm and hand, this second statement of Sherrif Tate's also gives Atticus grounds to motion to dismiss the case, which he sadly does not do.
Last, Bob Ewell, Mayella's father, serves as the only eyewitness in the trial. He testifies hearing Mayella scream inside the house and running up to the window to see "that black nigger yonder ruttin' on my Mayella" (Ch. 16). However, Ewell's testimony is later contradicted by Mayella's own testimony, in which says she saw her father "standing over [her] hollerin' who done it, who done it?" (Ch. 18). If Ewell had truly witnessed the event, he would have had no reason to ask Mayella who the culprit was, which helps to expose the Ewells' lies.
Four witnesses took the stand at the trial of Tom Robinson in To Kill a Mockingbird. They were (in order):
- Sheriff Heck Tate. Tate testified that most of his information was second-hand (from Bob Ewell) and that Mayella received no medical treatment following the assault. Atticus eventually determined that Mayella had bruise marks around her entire neck and that she was bruised on the right side of her face.
- Bob Ewell. Bob claimed that he saw Tom rape Mayella, and Atticus got Bob to admit that he was left-handed.
- Mayella Ewell. Mayella contradicted her own testimony (and that of Bob's) before finally refusing to answer any more of Atticus's questions.
- Tom Robinson. Tom claimed that Mayella first kissed him and that he ran away when Bob appeared. His most damning evidence came when he admitted to the prosecutor, Horace Gilmer, that he "felt sorry" for Mayella. Atticus's defense was that Tom's crippled left arm prevented him from causing the damage to Mayella's neck and face--and that it was probably Bob who beat his own daughter.
The four witnesses in Tom's trial were Sheriff Heck Tate, Bob Ewell, Mayella Ewell, and Tom Robinson.
Sheriff Tate says that he got most of his information second hand, mostly from Bob. He also says that Mayella did go to the doctor and the right side of her face was bruised.
Bob Ewell testifies that he had seen Tom rape Mayella. It also comes to light that Bob is left handed.
Mayella is the next witness. Her testimony changes while on the stand, until she refuses to testify anymore.
Tom takes the stand in his own defense. He tells the court that he helped Mayella with some things around the house. He said that he felt sorry for her but would never do anything to hurt anyone. Atticus also shows the court that Tom is right handed and can't even move his left hand up.
Atticus has done his job. He has proved that Tom is innocent and that there is no physical way he could have harmed Mayella. He also goes to prove that it was most likely Bob who injured his own daughter. Although Atticus has done everything he can and proved that Tom is innocent, Atticus knows the jury would find him guilty. There is no way a black man would get a fair trial in Maycomb. Atticus proves without a shadow of a doubt that Tom is innocent, but because Tom is a black man, he is found guilty and will lose his life.