This study investigates the association between air-lead levels and crime rates across 2,772 U.S. counties. Data for the analysis come from the Environmental Protection Agency, the Bureau of Census, and the Federal Bureau of Investigation. Results suggest that air-lead levels have a direct effect on property and violent crime rates even after adjusting for general levels of air pollution and several structural covariates of crime. We also find that resource deprivation interacts with air-lead levels. The association between air-lead levels and crime rates-property and violent-is strongest in counties that have high levels of resource deprivation and weakest in counties that have low levels of deprivation. This interaction is consistent with arguments and evidence in the health care literature that populations most at risk of lead poisoning are least likely to get the resources required to prevent, screen, and treat the illness.