The proposed research will implement an experimental design to assess effects that two hot spots strategies (collaborative problem solving and directed patrol), relative to control conditions, have on public perceptions of police legitimacy, fear, and willingness to act to promote collective efficacy. The design contrasts a traditional enforcement-oriented hot spots approach to place-based problem solving responses expected to change the routine activities of places over the long term. Forty-five of the hottest spots for reported crime in St Louis County, Missouri will be randomly assigned to one of three experimental conditions for six months. A time series crime-analysis and a multi-level analysis of data from three waves (pre-post-post) of adult citizen surveys (panel surveys) expected to produce 30 respondents per hot spot and 12 in each catchment area will examine the effects on crime and public opinion as well as displacement and diffusion of benefits. Officer surveys will inform about the challenges of HSP and provide recommendations for the future.