To understand how some criminals become dangerous and violent, criminologists must study the criminals' social experiences. Eight adult male offenders who had been convicted of at least two prior violent crimes and 30 young male and female novice offenders serving sentences for serious violent crime were interviewed at length and asked to identify the social experiences that made them carry out dangerous and violent acts. Their responses were compared with those of young adult male non-violent criminals and non-violent domestic assault victims. Violent dangerous criminals reported childhood social experiences of brutalization, which consisted of violent subjugation, personal horrification, and violent coaching by authority figures. After the brutalization experiences, they reported a belligerency phase and, later, a third phase in which they themselves carried out violent performances against others. A fourth phase finds the criminal acting in a virulent manner and carrying out violent attacks without provocation on others. The theoretical and policy implications of the four stages are discussed in detail. 40 footnotes.