The Illinlois Supreme Court had already held that the Second Amendment protects a right to carry guns in most public places, and in today's People v. Chairez it likewise rejected a ban focused on carrying within 1000 feet of parks:

The State argues that the conduct of possessing a firearm within 1000 feet of a public park is unprotected by the second amendment because the prohibition falls within Heller's declaration that "laws forbidding the carrying of firearms in sensitive places such as schools and government buildings" do not violate the second amendment rights of those prosecuted under such laws….

Beyond Heller's two examples of "sensitive places," i.e., "schools and government buildings," the Supreme Court has not yet provided a list of additional sensitive places that fall outside the second amendment protection or given any guidance on the breadth of its statement…. We, however, need not address whether the 1000-foot firearm restriction falls outside of the ambit of the second amendment because we agree with the approach taken by other courts that assume some level of scrutiny must apply to Heller's "presumptively lawful" regulations….

[This] analysis begins with a balance of considerations where the quantity and persuasiveness of the State's evidence required to justify the challenged restrictions varies depending on how much it affects the core second amendment right to armed self-defense and whose right it affects. The rigor of this means-end analysis "depends on 'how close the law comes to the core of the Second Amendment right and the severity of the law's burden on the right.'" The closer in proximity the restricted activity is to the core of the second amendment right and the more people affected by the restriction, the more rigorous the means-end review. If the State cannot proffer evidence establishing both the law's strong public-interest justification and its close fit to this end, the law must be held unconstitutional….

[N]either Heller nor McDonald expressly limited the second amendment protections to the home…. We find that the 1000-foot firearm restriction … directly implicates the core right to self-defense …. [It] prohibits the carriage of weapons in public for self-defense, thereby reaching the core of the second amendment. Although the firearm restriction at issue is not a comprehensive statewide ban, like in Moore or Aguilar, the restriction is not minimal. The firearm restriction not only covers a vast number of public areas across the state, it encompasses areas this court held in Mosley to be areas where an individual enjoys second amendment protection, i.e., public ways….

As to the second variable on the sliding scale, the severity of the law's burden on the right, the law at issue affects the gun rights of the entire law-abiding population of Illinois …. As in those cases, the law functions as a categorical prohibition without providing an exception for law-abiding individuals. It is therefore a severe burden on the recognized second amendment right of self-defense.

All of this suggests that elevated intermediate scrutiny should apply. And under this more rigorous review, the government bears the burden of showing a very strong public-interest justification and a close fit between the government's means and its end, as well as proving that the "public's interests are strong enough to justify so substantial an encumbrance on individual Second Amendment rights." That means the State must establish a close fit between the 1000-foot firearm restriction around a public park and the actual public interests it serves….

We certainly accept the general proposition that preventing crime and protecting children are important public concerns. After all, "[g]uns are inherently dangerous instrumentalities." The State, however, cannot simply invoke these interests in a general manner and expect to satisfy its burden…. [T]he State provides no evidentiary support for its claims that prohibiting firearms within 1000 feet of a public park would reduce the risks it identifies. Without specific data or other meaningful evidence, we see no direct correlation between the information the State provides and its assertion that a 1000-foot firearm ban around a public park protects children, as well as other vulnerable persons, from firearm violence….

There is another flaw in the State's position. The State claims that the restriction is not overly burdensome because there are areas throughout Illinois where one could exercise their core second amendment right…. Indeed an individual can preserve an undiminished right of self-defense by not entering one of the restricted areas. But the State conceded at oral argument that the 1000-foot firearm restriction zone around a public park would effectively prohibit the possession of a firearm for self-defense within a vast majority of the acreage in the city of Chicago because there are more than 600 parks in the city. Aside from the sheer number of locations and public areas that would qualify under the law, not only in the City of Chicago, but throughout Illinois, the most troubling aspect is the lack of any notification where the 1000-foot restriction zone starts and where it would end.

Innocent behavior could swiftly be transformed into culpable conduct if an individual unknowingly crosses into a firearm restriction zone. The result could create a chilling effect on the second amendment when an otherwise law-abiding individual may inadvertently violate the 1000-foot firearm-restricted zones by just turning a street corner. Likewise, in response to a question at oral argument, the State conceded that an individual who lives within 1000 feet of a public park would violate [the law] every time that individual possessed a firearm for self-defense and walked to his or her vehicle parked on a public street.

To remain in compliance with the law, the State said that the individual would need to disassemble his or her firearm and place it in a case before entering the restricted zone. This requirement, however, renders the ability to defend oneself inoperable and is in direct contradiction to this court's decisions in Aguilar, which recognized that the right to carry firearms for self-defense may be especially important when traveling outside of the home, and perhaps even more important than while at home. Moreover, the State's proposition conflicts with Heller's decision that struck down the requirement that firearms be kept "unloaded and disassembled or bound by a trigger lock" because it "makes it impossible for citizens to use them for the core lawful purpose of self-defense."