Study data were obtained with the cooperation of officials and line staff in the California Department of Corrections and in two metropolitan police departments. Persons individually interviewed by peers were 32 officers in the Oakland Police Department who had suffered assaults, 19 men who had assaulted the police officers, 44 prison inmates involved in violent incidents, and 33 parolees with violent records. The content of the interviews was structured to determine the motives, attitudes, and preconceptions of the persons as they were involved in violent incidents. Analysis of the interview data included the diagramming of each violent incident and the summarizing of the interviewees' violent involvements. The typological classification of the violent men consists of 10 categories, each describing one approach to interpersonal situations that promotes violence. One out of four sample subjects are categorized as 'self-image promoters,' who are committed to presenting themselves as formidable and fearless. The discussion of implications covers the criminal justice system's effectiveness in deterring violence, the identification and classification of violent men, and strategies for changing violent behavior. An appended code for interpersonal situations involving assaults on police and subject index.