Murders in the Windy City have plummeted since the Illinois legislature enacted its concealed weapon carry law, and the state Supreme Court upheld a person’s right to carry firearms outside the home.

The Chicago Police Department posted the city’s 2014 first quarter crime figures Tuesday, indicating the lowest number of homicides since 1958, according to local ABC affiliate Eyewitness 7 News, which reported:

The first three months of the year saw 6 fewer murders than the same time frame in 2013–a 9 percent drop–and 55 fewer murders than 2012, according to a statement from Chicago Police. There were 90 fewer shootings and 119 fewer shooting victims, drops of 26 and 29 percent respectively, according to police statistics. Compared to the first quarter of 2012, there have been 222 fewer shootings and 292 fewer shooting victims.

So what’s changed that could possibly account for such a dramatic fall in a city that was fast becoming known for its homicide rates — especially in its notorious South Side neighborhoods?

In July, the Illinois legislature overrode Democratic Gov. Pat Quinn’s veto to make The Land of Lincoln the final state in the country to have a concealed firearm carry permit law.

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Two months later, the Illinois Supreme Court added an exclamation point to the lawmakers’ action. It unanimously held that the Second Amendment protects one’s right to carry a firearm outside the home.

Independent Journal Review reported:

Gun crime experts John Lott, Jr. and David Mustard made the famous argument in “Crime, Deterrence, and Right-to-Carry Concealed Firearms” that: “When state concealed handgun laws went into effect in a county, murders fell by 8.5 percent, and rapes and aggravated assaults fell by 5 and 7 percent.” More guns mean less crime. Gary Kleck, PhD., also a gun crime expert, found that the crime deterrence effect of firearms possession is significant: sophisticaed statistics suggest three to four crimes are stopped by a handgun than are committed in the United States every year.

Tuesday’s tragic shooting at Fort Hood, Texas, should teach us, if nothing else, “gun-free zones” — whether they be schools, cities or military bases — don’t work. They’re a deterrent to a law-abiding citizen; they’re an invitation to a criminal.