Deadly force research typically does not distinguish between shootings by on-duty and off-duty police. This article uses Philadelphia police shooting data from two time periods (1970-1978 and 1987-1992) and a unique quasi-experimental design to examine the comparative effects upon on- and off-duty police shootings of an administrative policy that limited police shooting discretion but that did not address questions of police weapons carrying and access to firearms. The article draws important distinctions between when to shoot and carry administrative policies and considers their impact on deadly force by on- and off-duty police.