Who is Isom Justice from Storming Heaven: A Novel and what is their importance?

This fun-loving son of Ermel Justice and best friend of Rondal is often a source for annoyance for the serious-minded C.J. Marcum. Isom seems to like everyone regardless of their race or level of wealth, and he takes his own family's wealth for granted as revealed by his free spending ways and his generosity. As Isom ages he does get more serious about important matters, but he never loses his delightful sense of humor and love for good times and company. Isom marries a daughter of C.J. Marcum and becomes the chief of police for Annadel in an effort to protect the town from the violence of the Baldwin-Felts agents.