All American Boys - Who was Quinn? How did he change throughout the novel?

Quinn serves as a foil to Rashad, He is a baskeball players, and his attempt to purchase beer illegally is the reason that he is a witness to Rashad's beating. Over the course of the novel, Quinn decides that rather than stand back and watch injustice, he is going to stand up for Rashad, even at the risk of personal sacrifice, as his support for Rashad means exposing a family friend, Paul Gullazzo.