Why is Cole Matthews banished to live alone on an island in Southeast Alaska for one year

At the beginning of the novel, Cole Matthews, a fifteen-year-old juvenile delinquent from Minneapolis, Minnesota, arrives on a barren island near the city of Drake in Southeastern Alaska in handcuffs. He is accompanied by two men of Tlingit Indian origin, named Edwin and Garvey, who are instructing him on the terms of his banishment to the island. In the first few chapters, we learn through flashbacks about why Cole has been sent to the island. After years of violence and trouble with the law, Cole took his criminal streak a step too far when he viciously beat a classmate of his named Peter Driscal onto the floor of his school sidewalk. Peter suffers head trauma, speech problems, and constant nightmares as consequences of Cole’s actions. Faced with the prospect of being tried as an adult and sent to prison, Cole is offered the path of Circle Justice to avoid prison by a corrections officer named Garvey. This program is of Native American origin and seeks healing of the criminal for reintroduction to society.