It seems pretty clear to everybody but the jury that Tom Robinson could not have committed the crimes for which he is charged. Although Atticus recognizes early that the jury can't be expected to take a black man's word over the word of a white man, he establishes some strong evidence that seemingly exonerates Tom.
- Since Mayella was beaten on the right side of her face, it must have been a left-handed person that struck her. Tom's left hand is "shriveled" and has only a good right hand; Bob is left-handed, writing his signature for Atticus with his left hand. They were the only two men present at the time of the attack.
- Sheriff Tate testifies that there were bruises all the way around her neck, meaning that someone used two hands to choke her. Again, Tom only has one good hand.
- In the days before the modern "rape kit," no medical evidence was taken concerning Mayella's attack. The charge of rape is unproven, since Mayella only says that Tom "done what he was after." No doctor tended to Mayella's injuries.
- Mayella contradicts her own testimony, telling Atticus,
"No, I don't recollect if he hit me. I mean yes I do, he hit me...
"Huh? Yes, he hit--I just don't remember, I just don't remember... It all happened so quick."
- Tom's own testimony seems to be more forthright and truthful than either Bob's or Mayella's.