In addition to the annual reports of the Saint Louis Police Department, this study examined the individual folders of a systematic random sample of 1,534 officers who joined the force from 1899 to 1970. Findings showed that officers appointed in the early part of the century typically had few shifts in assignment and even fewer transfers among divisions than their counterparts recruited during the postwar period. Consequently, the latter were much less likely than the former to remain a considerable time at the same task. Still, the number of officers who received multiple transfers remained modest even in the postwar period. The overwhelming majority of officers who shifted among branches consisted of veterans of at least 10 years service. Although the magnitude of variation around average patterns of change in police careers decreased over time, evidencing a slight trend toward greater standardization in careers, no typical pattern ever emerged. The Saint Louis Police Department never developed the kind of routinization in assignments that might be expected in bureaucratic growth. This remained the case even regarding the most basic characteristic of careers -- stability in employment -- and despite department efforts to achieve this goal. Since the failure to establish a uniform, coherent career pattern has been true for one of the most advanced and reform-conscious police forces in the Nation, this strongly suggests that similar patterns exist elsewhere. Tabular data and 13 references are provided. (Author summary modified)