Tom the Cripple. Tom's crippled left arm made it physically impossible for him to have committed the crime of assault or rape upon Mayella. The bruises found around her neck and the bruised right side of her face could only have been made by a man with two strong hands--a man " 'who led almost exclusively with his left.' " Additionally, no medical evidence existed to prove that Tom raped Mayella, or that Mayella was actually sexually assaulted at all.
Tom the Friend. Tom had helped out Mayella before, and he " 'felt right sorry for her' " due to the hard life she spent in the Ewell household. Mayella also trusted Tom enough to invite him into her house, knowing that he would do as she asked. He knew that he put himself at risk entering a white man's house, but he was willing to do so in order to help out Mayella.
Honest Tom vs. Bob the Liar. Tom's skin color prevented the jury from accepting Tom's word over that of Bob Ewell, but the innocent children had no problem accepting Tom's story over Bob's. Bob told the jury that he witnessed Tom " 'ruttin' on my Mayella,' " though Mayella's own testimony offered no specifics concerning the supposed rape. Tom's honest response about running away when Bob appeared--" 'if you was a nigger like me, you'd be scared, too' "--seemed a more likely scenario than the tale told by Bob. Tom's statements also placed the possibility of guilt upon Bob: Mayella had already admitted that she feared her father when he was drunk, and she told Tom that her father's kisses " 'don't count.' " But as Tom was leaving, he heard Bob cry out to Mayella,
"... you goddam whore, I'll kill ya." (Chapter 19)