We report novel empirical estimates of the race-specific effects of larger police forces in the United States. Each additional police officer abates approximately 0.1 homicides. In per capita terms, effects are twice as large for Black versus White victims. Larger police forces also make fewer arrests for serious crimes, with larger reductions for crimes with Black suspects, implying that police force growth does not increase racial disparities among the most serious charges. At the same time, larger police forces make more arrests for low-level "quality-of-life" offenses, with effects that imply a disproportionate impact for Black Americans.