The (un)known universe: Mapping gangs and gang violence in boston

The experience, obseroations, local knowledge, and historical perspective of working police officers and others with routine contact with offenders, communities, and criminal organizations may represent an important underutilized resource for describing, understanding, and crafting interventions aimed at crime problems. Mapping and other informationcollecting and -ordering techniques, usually aimed at formal police data, can also be used to good effect to capture and organize these experiential assets. This chapter describes one such exercise carried out as part of a project to apply problem-solving techniques to youth gun violence and gun markets in Boston. A working group comprised of Harvard University researchers, police officers from the Boston Police Department's Youth Violence Strike Force, probation officers covering high-risk neighborhoods, and city-employed gang-mediation "street workers": estimated the number and size of the city's gangs; mapped their turf; mapped their antagonisms and alliances; and classified five years of youth victimization events according to their connection (or lack thereof) to this gang geography. The products of these exercises provide: a "snapshot" of Boston's gang turf; an estimate of gang involvement in high-risk neighborhoods; a sociogram of gang relationships; and an estimate of Boston gangs' direct contribution to youth homicide victimization.