Answer:
We know that Tom Robinson could not have done what he is accused of because the evidences presented in the courtroom show that it was "physically impossible" for him to be the culprit, and that proves his innocence, and the state has not given any medical evidence that the crime even took place.
The climax of Atticus' closing statement is this "Our courts have their faults, as does any human constitution, but in this country our courts are great levellers, and in our courts all men are created equal."
Explanation:
In cross-examining the witnesses in defense of Tom Robinson Atticus revealed that most of Mayella Ewell's bruises are on the right side of her face, meaning she was struck with a left hand, and Tom Robinson's left arm is completely useless. However he pointed out that Bob Ewell is left-handed, which suggests that he might have been the one responsible for his daughter's injuries.
Atticus also proved that Mayella and her father are lying in giving their testimonies, and he explained the reason Mayella blames Tom Robinson is because of her guilt for kissing Tom previously, which is a violation of the social "code" that prohibits interracial relationships.
In his closing statement Atticus urged the jurors not to let their racial prejudice influence their verdict, he told them, "Gentlemen, a court is no better than each man of you sitting here before me on this jury. a court is only as sound as its jury, and a jury is only as sound as the men who make it up. I am confident that you gentlemen will review without passion the evidence you have heard and come to a decision, and restore this defendant to his family. In the name of God, do your duty."
