In Lee's To Kill a Mockingbird, how do you know if Bob Ewell is a mockingbird?

Throughout the novel, mockingbirds are symbolized as innocent characters who seek to bring joy into the world and are relatively helpless against harmful beings. In Chapter 10, Atticus tells the children that they can shoot all the bluejays that want, but it is a sin to kill a mockingbird. Maudie elaborates by telling the children that mockingbirds do nothing but make music for people to enjoy. She also says that they don't nest in corncribs or eat up people's gardens. Bob Ewell would certainly not be considered a metaphorical mockingbird, but could be identified as a bluejay throughout the novel. Bob is the most despicable individual in Maycomb County and is notorious for being a rude alcoholic. Bob is the novel's antagonist who harms his children, Tom and Helen Robinson, and attempts to murder Jem and Scout. He is not innocent like mockingbirds and causes trouble throughout the entire novel. The two most notable characters who would be considered mockingbirds would be Boo Radley and Tom Robinson. They are both magnanimous, innocent individuals who are relatively helpless against evil people. Bob Ewell does not display any redeeming qualities and therefore would not be considered a mockingbird.