Police shootings in Philadelphia: An analysis of two decades of deadly forc

This dissertation studies police use of deadly force in the context of a discretion control problem and examines the role of internal and external working environments on police shooting behavior. The research uses data that offer an opportunity to clarify the nature of the relationship and define more precisely the relative importance of specific aspects and discretion controls within these environments. The research's conceptual model shows that situational factors mediate the influence of both working environments on police shooting behavior. The study uses interrupted time series analysis, a quasi-experimental design, and bivariate and multivariate analyses to further illuminate the nature of police use of deadly force and its determinants.;Findings suggest that the formal, external discretion controls are not, by themselves, effective in limiting deadly force discretion. The internal police working environment, however, plays an important role in limiting deadly force discretion, both as a direct control and as a mitigating or intervening influence for external controls. Philadelphia's experience illustrates how the internal environment can resist discretion control policies, including restrictive administrative rules, and serve as an effective barrier to reform efforts. Findings from the non-equivalent dependent variables design suggest that on- and off-duty shootings are different phenomena and raise questions regarding the effectiveness and appropriateness of overall administrative approaches in controlling off-duty deadly force discretion.;Bivariate and multivariate analyses showed that there is little consistency over time with regard to what situational factors exhibit relationships with the various definitions of elective shootings. The research developed predictive risk models for gun-assaultive and non-assaultive incidents and illustrated how the presence of certain variables helps to distinguish between different types of deadly force incidents.;Overall, the findings show that the dynamics of non-elective and elective deadly force incidents and their influences are unique and should be considered separately. The internal and external working environments play a more prominent role in elective encounters, while situational factors are less important. In non-elective encounters, however, situational factors largely dictate an officer's decision to use deadly force and outweigh the relative influence of the working environments.