Actually it's the whole liberal edifice that's responsible. If criminal black youths had been cracked down on going back fifty years ago, we wouldn't have the problems we now have. Things changed a bit for the better when they made the decision to keep violent offenders in prison longer about 20-30 years ago, but there's still a very large segment of black youths who are basically feral. Until they're shown, by very harsh methods since gentle persuasion doesn't do much of anything, the error of their ways, cities are going to have these incidents. Which seem to have increased exponentially since 2008.
fe·ral [ frəl ]
1. gone wild: describes animals or plants that live or grow in the wild after having been domestically reared or cultivated
2. savage: similar to or typical of a wild animal, or living wild