Sociologist Andrew Papachristos focuses his studies on urban neighborhoods, social networks, street gangs, violent crime, and gun violence. As a Robert Wood Johnson Health and Society Scholar at Harvard University, Andrew will expand his use of network analysis to study crime in U.S. cities, paying particular attention to the way violence diffuses among populations of youth. During a break in a roundtable on collaborations between public health and public safety, he discusses how social network analysis can aid crime prevention.