Abstract The paper investigates the relationship between social interactions and crime for the case of a developing country that has shown increasing crime rates in recent years. Social interactions are defined as any type of relationship of an individual with other individuals that can affect his/her behavior. We use a unique data set to investigate whether interaction among individuals of the same family and/or a neighborhood or community had any influence on the criminal behavior of individuals who are already convicted. The data set was constructed through interviews at the Papuda State Jail in Brasilia, Brazil. The results are in line with a growing literature on the study of criminal behavior and demonstrate that strengthening family and community relationships can be a desirable way of fighting crime in the context of developing countries.