Who is Philip McGuane from Gone for Good and what is their importance?

Philip McGuane is one of Ken and John's childhood friends. He is the head of a crime organization, and he is described ruthless, violent, and manipulative. McGuane regularly uses his offices for killings and edits film footage to make it appear that the dead men were alive when they left his office alive. District Attorney Joseph Pistillo is determined to bring him to justice.