Research demonstrates that crime concentrates at relatively few microplaces, and changes at a small proportion of locations can have a considerable influence on a city’s overall crime level. Yet there is little research examining what accounts for change in crime at microplaces. This study examines the relationship between two mechanisms for place-based improvements – private investment in the form of building permits and public regulation in the form of municipal code enforcement – and yearly changes in crime at street segments. We use longitudinal data from six cities to estimate Spatial Durbin Models with block group and census tract by year fixed effects. Building permits and code enforcement are significantly associated with reductions in crime on street segments across all cities, with spatial diffusion of benefits to nearby segments. These findings suggest public safety planning should include efforts that incentivize and compel physical improvements to high crime microplaces.