This paper examines the relationship between inequality and crime using data from urban counties. It finds that inequality has a strong and robust impact on violent crime, with an elasticity above 0.5, while it has no significant effect on property crime. Poverty and police activity have significant effects on property crime but little on violent crime. Property crime is well explained by the economic theory of crime, while violent crime is better explained by strain and social disorganization theories. The study uses data from 1991 for all metropolitan counties to analyze the link between crime and inequality. It distinguishes the effects of inequality from those of poverty by including measures of deprivation such as unemployment and poverty rates, percentage of nonwhite population, and percentage of female-headed families. Police expenditure per capita is used as a measure of the deterrent effect of police activity. The results show different patterns of behavior between property and violent crime. Both types of crime are positively influenced by the percentage of female-headed families and population turnover, and negatively related to the percentage of population aged 16–24. Property crime is largely unaffected by inequality but significantly influenced by poverty and police activity, while violent crime is little affected by poverty and police activity but strongly aggravated by inequality, with an elasticity in excess of 0.5. These effects are robust across different measures of inequality and combinations of explanatory variables. The study also finds that inequality is associated with crime through its link to poverty. Social disorganization theory considers factors that weaken the effectiveness of informal social controls, such as poverty, racial heterogeneity, and residential mobility. Strain theory argues that inequality leads to frustration and the desire to commit crime. The economic theory of crime suggests that inequality increases crime by placing low-income individuals next to high-income individuals. The paper discusses the three main ecological theories of crime: Becker's economic theory of crime, Merton's strain theory, and the social disorganization theory of Shaw and McKay. It also presents econometric specifications and regression results, showing that police activity has a strong deterrent effect on property crime but little impact on violent crime. The study concludes that inequality has a significant impact on violent crime but not on property crime, and that the three ecological theories provide complementary explanations for the relationship between crime and inequality.This paper examines the relationship between inequality and crime using data from urban counties. It finds that inequality has a strong and robust impact on violent crime, with an elasticity above 0.5, while it has no significant effect on property crime. Poverty and police activity have significant effects on property crime but little on violent crime. Property crime is well explained by the economic theory of crime, while violent crime is better explained by strain and social disorganization theories. The study uses data from 1991 for all metropolitan counties to analyze the link between crime and inequality. It distinguishes the effects of inequality from those of poverty by including measures of deprivation such as unemployment and poverty rates, percentage of nonwhite population, and percentage of female-headed families. Police expenditure per capita is used as a measure of the deterrent effect of police activity. The results show different patterns of behavior between property and violent crime. Both types of crime are positively influenced by the percentage of female-headed families and population turnover, and negatively related to the percentage of population aged 16–24. Property crime is largely unaffected by inequality but significantly influenced by poverty and police activity, while violent crime is little affected by poverty and police activity but strongly aggravated by inequality, with an elasticity in excess of 0.5. These effects are robust across different measures of inequality and combinations of explanatory variables. The study also finds that inequality is associated with crime through its link to poverty. Social disorganization theory considers factors that weaken the effectiveness of informal social controls, such as poverty, racial heterogeneity, and residential mobility. Strain theory argues that inequality leads to frustration and the desire to commit crime. The economic theory of crime suggests that inequality increases crime by placing low-income individuals next to high-income individuals. The paper discusses the three main ecological theories of crime: Becker's economic theory of crime, Merton's strain theory, and the social disorganization theory of Shaw and McKay. It also presents econometric specifications and regression results, showing that police activity has a strong deterrent effect on property crime but little impact on violent crime. The study concludes that inequality has a significant impact on violent crime but not on property crime, and that the three ecological theories provide complementary explanations for the relationship between crime and inequality.