That seems to be more of an community issue like kid's growing up in poor conditions to gang member parents and not getting the right education and not enough free time activities provided, there's a lot of stuff going wrong on Chicago's South Side.
And i'm not really that deep into the topic of gun control , but a lot of people in for example switzerland are strapped and almost no gun violence happens
Statistics from 2013

To the OP : That's kind of hypocritical when so many people die to violence every day in the world just because it happened in europe doesn't make it better or worse than for example when a bomb explodes in pakistan , we are just used to those news and don't really care anymore.
The world has always been crazy , we are animals after all...
You should check out the documentary HyperNormalisation by Adam Curtis it's pretty good and it addresses the complexity of the world