In Part 1 of the research project, data were collected on violent incidents in 1998 from the police regions Rotterdam-Rijnmond and IJsselland. Offender and victim profiles was described. Results from Part 1 showed that street violence is mainly found in neighborhoods (35 percent), traffic (24 percent), and entertainment areas or areas with a high concentration of bars, cafes, discos, and restaurants where people go out (19 percent). The level of street violence was judged disproportionate in about one in four incidents involving no more than one perpetrator and one victim. In street violence between groups, half of the incidents were disproportionate. Roughly half of the neighborhood incidents showed disproportionate violence levels; in traffic this was one third and in entertainment areas most street violence was disproportionate. The aim of Part 2 was to acquire insight into the process of street violence as well as into the backgrounds and motives of the persons who were involved in street violence. A selection of 60 incidents of street violence was analyzed: 16 traffic incidents, and 22 incidents for both the neighborhood and entertainment area contexts. Information was gathered from police files and interviews with offenders, victims, and witnesses were conducted. There were two main causes for street violence in traffic: asocial behavior and unintentional traffic violations. Violence perpetrated in entertainment centers could be labeled intentional violence with mutual irritations and trivial causes. Neighborhood violence started because of serious as well as trivial reasons. The findings lead to the conclusion that a variety of motives, background, and situational factors should be taken into account in order to better understand street violence. Street violence doesn’t have a singular cause, and a number of personal characteristics and personality traits can be indicated that may increase the chance of committing violence against strangers.