Criminologists have largely ignored the issue of bystander intervention. Existing research has been done by legal scholars and social psychologists interested in 'Good Samaritanism.' As a result, research has treated a criminal event as just another type of emergency and crime intervention as a variety of rescue instead of as crime control. Social psychology's methodology, its emphasis on situational parameters, and its underlying concern with altruism have precluded a more complete understanding of bystander response in general and of bystander response to crime in particular. The need to protect experimental subjects has also prevented most study of direct intervention, which has been assumed to involve processes and types of people similar to those of indirect intervention. However, the empirical literature seems to indicate that direct interveners are more likely than indirect interveners to be males, to be impulsive, to feel competent, and to be motivated by hostility toward the offender, but less likely to be morally motivated and to be influenced by others. On the other hand, no significant differences appear to exist between intervenors and nonintervenors on social, demographic, or personality factors. Some differences appear when comparing bystander orientations toward the victim and toward the offender, however. Discussions of specific research findings, notes, and 102 references.