How does the death of Tom Robinson represent killing a mockingbird in To Kill a Mockingbird?
Tom Robinson is one of the symbolic human mockingbirds of To Kill a Mockingbird. Along with most of the children in the story--particularly Jem, Scout and Dill--Tom (and Boo) fit the description of the songbird that Miss Maudie describes to Scout.
Mockingbirds don't do one thing but make music for us to enjoy. They don't eat up people's gardens, don't nest in corncribs, they don't do one thing but sing their hearts out for us. That's why it's a sin to kill a mockingbird.
The mockingbird represents innocence and sweetness, childlike attributes that can also be found in Tom and Boo. Tom is an honest and hard-working married man who comes to Mayella's aid out of sympathy for her. Poor and crippled, he is a sympathetic character even before he is unjustly accused of raping Mayella. When he is found guilty, things seem bad for Tom; but when he is murdered, he becomes even more symbolic of the mockingbird: Innocent of anything but trying to make people happy, Tom suffers the fate that Miss Maudie warns Scout about.
Throughout the novel, Miss Maudie recognizes the mockingbird as a songbird that does nothing in life other than to bring music to the ears of all those around it. It is essentially the epitome of selflessness and innocence. Tom, as we especially learn throughout the trial, is a mockingbird. He has done nothing but served his fellow man and woman and honor his wife and family. When he rebukes the advances of a Mayella, he is quickly relegated as an evil outcast by one segment of society. His ultimate conviction and murder posits the notion of sin - it is a sin that such charges and death were brought upon an innocent man as it is a sin to kill a mockingbird, a creation of innocence.