In what ways does Harper Lee use Tim Johnson as a symbol for other people and ideas in To Kill A Mockingbird?

In To Kill A Mockingbird, the brief appearance of Tim Johnson is crucial in understanding the court case and establishes a strong symbolic connection to Tom Robinson’s later appearance.  

The first indication of this is the strong similarity in the names of the two characters. Another similarity between the two is the fact that they are both physically paralyzed. For example, Tim Johnson is described as ‘lopsided’ and Tom Robinson is described as looking ‘oddly off balance, his left arm is fully twelve inches shorter than his right’.  The rabies infection that Tim has is reflected in Tom’s being subject of a false accusation of rape. Both of them are innocent and they have not chosen to be in the situation that they are in. Furthermore, the two words ‘rabies’ and ‘rapist’ start with the same syllable which strengthens the symbolic connection between the two.

Harper Lee could be building this connection in order to show that Maycomb doesn’t see Tom Robinson as a person but as an animal like Tim Johnson. Just like the rabid dog is sickening, so are the presumptions made by the residents of Maycomb.