Economic analysis of infectious diseases emphasizes the self-correcting character of epidemics, as rising risk of infection causes potential victims to take self-protective measures. We apply the analysis to crime, showing how rational potential victims of crime will take increased self-protective measures in response to rising crime rates, causing those rates to moderate. Victim responses to crime can offset public expenditures on crime control; this implies that there may be a "natural" rate of crime that is difficult for the public sector to affect. We show that victim responses to crime can impart a cyclical pattern to crime rates and discuss the implications of our analysis for gun control and present empirical evidence concerning the responsiveness of self-protective measures to crime rates and the cyclical pattern of those rates.