You have to get the statistics from where open and concealed carry are allowed to where there are very restrictive gun laws like Washington DC, the strictest, which has the highest gun related deaths in the US, 24.5 per 100,000. And that figure is fudged since in NY if you're shot and wounded with a gun it goes down as an assault but if you die the next day that assault isn't changed just a notation put in the file so that 24.5 is more like 30-35. Every major mass murder involving guns in the US since the 1950's has been in one of these gun free zones, Liberal Nirvana.