Yep, there are sadly enough of them to make a documentary about it. Ireland's Teen Killers examine cases where young people have killed to attempt to get an understanding of their motivations. Former prison governor John Lonergan, psychologist David Carey, barrister Seamus Clarke and criminologist John O'Keeffe bring their professional insight and expertise to bear on each case, which includes that of Darren Goodwin, who was 15 when he killed 14-year-old Darragh Conroy in 2003 with a hammer he had taken from his metalwork class at school.