It was probably not unusual for The Maycomb Tribune Editor B. B. Underwood to be at his office on a Sunday night; after all, he lived above the office on the second floor, and he could usually be found there gathering news for the next issue while sipping on his ever-present jug of cherry wine. But Underwood would be one of the least expected citizens in Maycomb to stand up and defend Tom Robinson. Atticus actually found it somewhat humorous that Underwood had been keeping an eye on him and the children from above the jail--armed with a shotgun--while he met with the lynch mob.
"You know, it's a funny thing about Braxton," said Atticus. "He despises Negroes. Won't have one near him." (Chapter 16)
Underwood may hate Negroes, but he was not about to allow the gang from Old Sarum take the law into their own hands. He
... simply figured it was a sin to kill cripples, be they standing, sitting or escaping. (Chapter 25)