Subjects were 100 perpetrators of violent crimes (murder, rape, robbery) and 100 controls. Subjects were administered various psychometric tests, and anamnestic data were obtained from family members, schools, and public agencies. Factorial analyses were used to develop an empirical typology based on eight bipolar personality features: emotional disposition, social attitudes, regulation of affect, psychic orientation (introversion, extraversion), cognitive organization, level of inner regulation of conduct, and social adaptation. On the basis of the similarity of factorial profiles, four personality profiles were specified: nonsocialized type, intellectually deficient type, neurotic (dysphoric and anxious) type, and emotionally adequate type. The first two types were characteristic of the violent delinquents, while the fourth type was characteristic of controls. Life data suggested the presence of both specific and nonspecific signals related to perpetration of future violent crimes. Specific signals included a history of verbal and physical aggressions; nonspecific signals included such nonagressive deviant behaviors as truancy, vagrancy, sexual promiscuity, and frequent contact with delinquent juveniles. The frequency of both these signals was greater in the delinquent types than in the nondelinquent (neurotic and emotionally adequate) types. 1 note.