Former child star and future Baretta tough guy Robert Blake stars in this shocking crime drama based on the true story of The Purple Gang, teenage hoodlums who terrorized Detroit during the bootlegging era. A prologue from a congressman and actual newsreel footage heighten the reality of the violent story. Blake plays psychotic "Honeyboy" Willard, a juvenile delinquent always in trouble for petty thefts and similar deeds. Cop Bill Harley (Barry Sullivan) is convinced that Willard's violent side can only be tamed by a stint behind bars. But a social worker wants to use modern methods of therapy to correct the teen's problems. When the social worker is found murdered, a brutal spree of hijacking, extortion, protection rackets, gambling, prostitution, and alcohol running ensues. As the gang battles rival groups and intimidates the authorities, one detective makes it his mission to break them.