How does Scout explain her understanding of why Heck Tate is not revealing that Boo killed Bob Ewell in Harper Lee's To Kill a Mockingbird?
Scout says that exposing Boo Radley to the newspaper and the public as the man who saved hers and Jem's lives would be "like shootin' a mockingbird."
In Chapter 30, Sheriff Tate finally convinces Atticus that it is best to spare Boo the exposure that would come from the public's knowing about his act of heroism in taking Bob Ewell's knife from him and stabbing the vindictive reprobate. Atticus sits looking at the floor because he abhors lies; however, he then tells Scout, "Mr. Ewell fell on his knife. Can you possibly understand?" and she reassures him, "Mr. Tate was right." Her father asks her what she means, and it is then that Scout replies, "Well, it'd be sort of like shootin' a mockingbird, wouldn't it?"
Scout reaches this conclusion after listening to Sheriff Tate and Atticus discuss what has caused the death of Bob Ewell. She understands that the sheriff wishes to spare the shy, reclusive Boo Radley the emotional disturbance of being in the public eye.
"I never heard tell that it's against the law for a citizen to do his utmost to prevent a crime from being committed...."
Sheriff Tate contends that it is a sin to put a man who has lived a hidden life into the "limelight" just for his act of trying to prevent a crime. He concludes that it is better to report that Bob Ewell has fallen on his own knife, which he intended to use on the Finch children, and then to close the case.