Organizations are expected to assess and respond to environmental conditions. For police agencies in the post-9/11 and post hurricane Katrina era, the environment includes assessing the threat posed by terrorism and disasters. We use organizational contingency and institutional theories to predict the permeability of local police chiefs’ assessments of various environmental threats and what factors affect the sensing process. We use survey data from 350 police agencies to explore the dimensionality of agency assessments on disasters, accidents, and terrorism. Our findings indicate that local police chiefs view environmental threats as having three dimensions. Additionally, institutional sovereigns have a greater influence on agency assessments of threat than do contingency factors.