Identify three examples of "mockingbirds" in the novel To Kill a Mockingbird and explain why.

The concept of a mockingbird as a creature who is innocent and does not bother anyone else and who holds no malice toward others. "To kill a mockingbird" holds the connotation of to destroy the innocence of this creature by harming it. Three mockingbirds--innocents who are harmed by gratuitous cruelty--are Boo Radley, Tom Robinson, and Dill Harris.

• Boo Radley

As a youth Boo became involved in some vandalism and other teen-aged pranks for which his father imprisoned him. Then, because of his forced reclusion, tall tales have been fabricated about him; He eats raw squirrels, he has blood-stained hands and a long jagged scar, he poisons pecans, and stares in windows at night, etc.; in short, he is vilified and made to seem ghoulish.

After Boo saves Jem, Heck Tate recognizes that Boo has been too sheltered all these years and would not be able to handle the notoriety of having been the one who has saved the Finch children's lives. This is why he urges Atticus to agree to the account of Bob Ewell's falling upon his own knife.

• Tom Robinson

Tom Robinson is an innocent man whose kindness becomes his undoing as he falls victim to the cruel Bob Ewell. For, Mayella is forced by her father to accuse Tom of rape when she is caught hugging Tom after falsely luring him into her house where he innocently has gone in order to help her break apart an old chiffarobe.
Knowing that he is a scapegoat of white society after a jury convicts him of a crime that all evidence proves he did not do, Tom tries to flee, and is shot and killed.

• Charles Baker Harris (Dill)

Living mainly in a make-believe world of his own creation, Dill is an innocent boy who, when exposed to the cruel biases of Mr. Gilmer as he questions Tom Robinson on the witness stand, is overcome with fear and emotion. When he breaks down and cries, Scout takes him outside. There Mr. Dolphus Raymond hears Dill, and he offers him some of his Coca-Cola that the townspeople have mistaken for alcohol. Mr. Raymond notices Dill's innocence of how "colored folks" are treated, and he says,

“Things haven’t caught up with that one’s instinct yet. Let him get a little older and he won’t get sick and cry. Maybe things’ll strike him as being—not quite right, say, but he won’t cry [about the "hell white people give colored folks] not he gets a few years on him.”

Dill has received a shock to his innocence when he realizes how blacks are really treated by some of the town. After this experience, Dill becomes cynical.