To what extent are bureaucrats’ views shaped by the organizational contexts that they enter? What role do preorganizational influences have? This study provides some answers to these questions by testing hypotheses drawn from organization and personality theories. Using survey and interview data from a longitudinal study, this article examines how police officers develop their attitudes about using force during their first 2 years on the job. This study shows that development is a mixture of socialization and self-selection. However, it moves beyond the “it’s both” explanation by showing which influences mattered most and at which times.