It could hold true, but Chicago seems to be a hot spot and it also shows that gun laws do not work.
Why do you think it's a hot spot Baldimo?
Besides, gun laws were mostly reversed in Chicago several years ago. I know because I live in Chicago and own several firearms. IIRC you live in some surrounding city and have for a number of years (if not decades).
I agree that some, if not most, gun laws won't work for curbing gang violence. Many of them might work to help keep crazy people from getting guns though. I don't know that too many teenage school shooters are going to feel comfortable going to 100 S Leamington in Chicago and buying a gun in a brown paper bag from a gang-banger out of the back of the trunk of a car.