Abstract: This thesis explores the effect of a subway network expansion on different crime outcomes.During the mid-2000s Santiago’s (Chile) subway system grew by nearly 50%. I use Difference in Differences and Event Study approaches, and a novel data set that looks at both the location of crimes and the offender’shomeaddress.Ifind that people living near the new stations committed fewer property crimes after they opened. Larceny falls around 45%,three to five years after the inaugurations. I also find a smaller negative effect on violence-related crimes. Exploring different mechanisms, I find that the Metro expansion helped reduce commuting time, and to increase wages and working hours.This set of results could imply that better connectivity helps reduce criminal activity by creating better job opportunities.