Again and again we are shocked by reports of rampages and shootings, some of which take place in schools - severe forms of violence often with a large number of victims. A man kills his wife and children, a pupil kills other pupils and teachers. Today this can happen anywhere, in Germany and elsewhere in the world. These incidents usually surprise us, apparently coming out of nowhere, without warning and cause us to ponder: Are such events really always spontaneous? Are such killers always males, even among adolescents? Are they outsiders, social outcasts? Do reports in the media in fact provoke such acts of violence or increase their probability? The authors are active in the research, early recognition and prevention of school shootings. Here, they try to give answers to these and other questions surrounding the spread, background and prevention of rampages and school shootings.