What does Lee show through Maycomb's lack of concern about Tom's death?

The town carries on with little talk of Tom's death. I think there is an undercurrent of shame buried somewhere deep below. Everybody knows the truth; their bigotry is just too strong. The silence and whispers about the affair illustrates the town's feelings of apprehension. I think also that Lee is pointing out that although there seems to be a lack of concern, people will not forget this happened.