Abstract
Police officers often serve as first responders to mental health and substance abuse crises. Concerns over the unintended consequences and high costs associated with this approach have motivated emergency response models that augment or completely remove police involvement. However, there is little causal evidence evaluating these programs. This preregistered study presents quasi-experimental evidence on the impact of an innovative "community response" pilot in Denver that directed targeted emergency calls to health care responders instead of the police. We find robust evidence that the program reduced reports of targeted, less serious crimes (e.g., trespassing, public disorder, and resisting arrest) by 34% and had no detectable effect on more serious crimes. The sharp reduction in targeted crimes reflects the fact that health-focused first responders are less likely to report individuals they serve as criminal offenders and the spillover benefits of the program (e.g., reducing crime during hours when the program was not in operation).