In cold blood by Truman capote, why does he describe Hickock and Smith?

Both characters play roles in the book. Tex John Smith is Perry’s father, a former rodeo rider who now resides in Alaska. Perry has mixed emotions when it comes to his father, but mainly he resents Tex John for holding him back as an adolescent. He plays a minor part in exploring Perry's nature. Dick is a major character who initiates the plan to rob the Clutters.