Abstract
In a recent bulletin, the World Health Organization detailed the violence prevention work, particularly on homicide, by Rodrigo Guerrero-Velasco in the city of Cali, Columbia, where he is also the mayor (Greenhouse, 2015). Guerrero-Velasco and his colleagues have used epidemiology to study the social problem of violence and found that guns, alcohol use, and social inequalities were strongly associated risk factors with violence, as were child abuse and organized crime in a community.