This longitudinal, prospective study used case material from 232 families in its analysis of effects of family environments on criminal behavior. Men who had participated in a crime prevention program were studied 40 years after their families had first been visited by counselors. The men's convictions for serious crimes provided a measure of the long-term impact of childhood environments. Serious crimes were defined as crimes that appeared on the Federal Bureau of Investigation Type-1 Index. Records describing the families were coded in terms of parental alcoholism, family structure and conflict, esteem of each parent for the other, and parental supervision, discipline, warmth, and aggressiveness. Analyses of the data revealed that families of criminals differed from families of noncriminals in many ways. Criminal rates tended to be low when family climate had been good. Maternal competence and control appeared to reduce crime. Families deficient along one dimension tended to be deficient along others as well. Combined deficiencies appeared to be particularly criminogenic. (RH)