Ok let’s talk about Chicago. Violent crime rates and specifically gun related fatalities have skyrocketed after the Supreme Court overturned a city ordinance banning the carry of handguns in the city in 2008. Then in 2013 the state / city got rid of a gun registry law and subsequently passed a concealed carry law.
Moreover the Chicago PD cites gang activity as well as the flow of guns from surrounding Suburbs and from (Republican) Indiana. There have been studies that day that 60% of the guns used in gang crime in Chicago come from other states. It’s not Chicago itself that’s the problem. It’s the surrounding states (Wisconsin + Indiana) that are hindering it.
You might ought to check your murder stats.. they were flat from '08-16... in 16 the CPD initiated a no stop policy and hands off policing in response to the Fergusson Riots..since then their solve rates have plummeted and they rely more on electronic surveillance than real police work..