The document discusses representations of social groups in the author's thriller opening. It shows three groups: a teenage boy, a man aged 20-30, and the general public. The teenage boy is portrayed positively as innocent and caring to challenge stereotypes of teenagers as troublemakers. Details like a loving note to his family create sympathy for him. The man is dressed formally, looking out of place, to represent his older age group but as a psychotic killer he does not reflect most people that age. The general public are shown as careless bystanders, representing their self-centered nature and willingness to ignore crimes.