In the beginning of the story, Boo represents the unknown. The children of Maycomb believe that anything that comes from the Radley's soil is poisoned, including the nuts and fruits on the trees. Jem yells at Scout once saying about the Radley property: "Don't you know you're not supposed to even touch the house over there? You'll get killed if you do" No one has ever died from touching something on the Radley property, yet the children continue to believe it to be true. They imagine Boo as a horrible monster that eats squirrels and rats with his bare hands who loves to kill children. They wonder about Boo and why he never leaves his house, but they really have no idea of whom he is. They make up games and stories pretending to be the Radley family, but stop when Atticus catches them. Boo Radley serves two essential purposes. At the beginning of the novel, Boo serves as a mystery to the children, giving them ideas for games, as well as a topic of conversation. As the story continues, it becomes clear that Boo embodies more character than most of the citizens of Maycomb, emerging as a symbol of what is truly just and right. Boo stands up for what he believes is right, no matter what people think of him. As the story continues, Boo becomes more of a symbol of kindness and bravery. He leaves presents for Scout and Jem in the hollow trunk of an old tree. He mends Jem’s pants and he covers Scout with a blanket during Miss Maudie's fire. This is Boo’s way of “singing” beautiful music.
The character of Tom Robinson is another unjustly treated mockingbird. Tom helps Mayella Ewell with her chores, not because she is white, but because he is a kind person and felt sorry for her. Tom, however, was not able to stop Mayella from grabbing him and wanting to kiss him. It was a black man’s words against a racist white community. After being killed attempting to flee from the confines of prison life, Tom, in an editorial by Mr. Underwood, is compared to, "a harmless songbird killed by senseless hunters."
The people of Maycomb misunderstand both Boo Radley and Tom Robinson. They are both simple creatures, comfortable lifestyles that do not revolve around the people of Maycomb. Because they are different and people do not know them for who they truly are, they are unjustly persecuted. They are misunderstood; they hold little social value, and are generally assumed guilty. The two plots are connected when Boo saves Jem and Scout’s life from Bob Ewell. Even though Boo is a physically weaker man, he shows no fear when it comes to protecting Jem and Scout's life. Tom Robinson is an innocent man, critised for the simple reason that he is black. Tom is not guilty of this crime, but is persecuted by the jury of Maycomb because they are afraid to stand up for what is right