Don't underestimate the role of the destruction of inner city public housing complexes in the reduction of violent crime. Gentrification might be a taboo word, but it has certainly played its role is reducing inner city crime. The drawback though is that it has pushed crime to the suburbs, particularly in the major cities. Violent crime was notoriously high in some of these housing complexes because a lot of these gangs could control entire buildings that served as a base for their narcotics distribution. Now the gangs are more sprawled out throughout the cities. It shouldn't be lost upon anyone though that it was the introduction of crack into the ghettos that made them deteriorate the 80s and 90s levels.