This article discusses the capacity of police research to draw meaningful and well-informed conclusions about long-range trends in policing. Major gaps in existing research on policing limit our ability to make definitive inferences about how the policing industry is changing. These gaps result in part from a lack of systematic, standardized, longitudinal data collection and analysis on the nature and outputs of police organizations in the United States. As a result, we know little about basic descriptive features of policing and how these features are changing over time. Lacking the ability to track even the most basic descriptive trends, the police research industry is at even more of a loss in developing careful empirical explanations of these trends. This article discusses some of these trends, summarizes what we know and what we do not know about them, and provides some recommendations for how the police research industry can improve its capacity to anticipate, describe, and explain trends in the police industry.