I read a very interesting article about Chit-cago's gang/violence/murder problems. Wish I had the link, but the gist was there is a thug culture prevalent amongst black culture in the south side population and the VAST majority of the murders are among them. Not really ground-breaking, but they put stats and analysis to what we all recognize. The plotting of shootings there is similar to Omaha. VERY localized to some specific areas. A third world enclave surrounded by a huge metropolis.
Of course the corruption and mis-management in Chicago is legendary and greatly magnifies the problem by avoiding solutions.