This thesis consists of three essays on the economics of crime and the judicial system. The first essay investigates the determinants of judicial performance. We show that more developed localities in Brazil, measured by higher income, educational level and urbanization concentrate the more productive courts and judges creating large disparities across the country. The second essay evaluates the impact of legal capacity measured as judicial performance on violent crimes in Brazil. We use a Regression Discontinuity Design and show that changes in the judicial district classification that depends on number of voters increases judicial performance and this change is associated with a decrease in homicide rates. The third essay assess the impact of women s protection laws - The Maria da Penha law introduced in Brazil in 2006 - on domestic violence. We use a differences-in-differences strategy and compare homicides rates of males and females before and after the passage of the law. We find that the law significantly reduced the female household homicide rates and these effects were concentrated in small municipalities.