What is the main theme Walter Dean Myers book Monster?

The primary theme of Monster reveals how the American legal system works to determine who committed a crime and how the criminal is punished. The book portrays the prison system through the eyes of a sixteen-year-old black teenager, who paints horrible images of life in jail, and this is just a detention center, not a penitentiary. Everyone who enters the system seems to be punished, guilty or not. Steve desperately wants to get out of prison, even if it means taking his own life. He also observes that the authorities take the prisoner's shoelaces and belt to keep the prisoner from committing suicide. Is prison really this bad? To Steve, it is the worst place in the world. However, he has yet to live a great deal of life. Compared to other prison situations that involve sanctioned torture and no due process, the Manhattan Detention Center is not so bad. Perhaps Steve's brush with the law this early in life will help him to take the straight path the rest of his life.