This paper measures heterogeneity in officers’ effects on reported crime and policing activities (stops, arrests, force use, and misconduct complaints) using Chicago administrative data. I estimate officer fixed effects for each outcome and compute their bias-corrected variances and covariances. Officers differ significantly in their effects on activities and crimes, with effects on serious crimes driving differences in effects on social costs. However, officers’ activity effects and crime effects are only weakly correlated, and activity effects and demographics explain little variation in crime and total-cost effects, suggesting that common measures of officer productivity poorly predict officers’ effectiveness at reducing crime.