Illinois Supreme Court Gun Ruling: Ban, Registration, Penalties

The Illinois Supreme Court gun ruling issued on August 11, 2023 upheld the Protect Illinois Communities Act, finding that the state’s ban on certain semi-automatic firearms and large-capacity magazines does not violate the Illinois Constitution. For gun owners in the state, that means the law is enforceable now: banned items cannot be bought or sold in Illinois, weapons legally owned before the ban must be registered through an endorsement affidavit, and strict rules govern where those grandfathered firearms can be taken. A separate federal challenge is still working its way through the Seventh Circuit, but nothing about that litigation changes what Illinois law currently requires.

What the Court Actually Decided

The case was Caulkins v. Pritzker. The plaintiffs did not argue that the ban violated the Second Amendment. They argued it violated the Illinois Constitution’s equal protection and special legislation clauses because the Act exempts peace officers, active law enforcement, retired law enforcement, and certain military members from its restrictions while binding everyone else.

The court rejected that theory. The majority found that the exemptions were rationally related to the training and duties of the exempt groups, which made them permissible classifications rather than unconstitutional special privileges. Because the plaintiffs never raised a Second Amendment claim at the trial court, the justices did not address that question at all. The ruling resolves the state constitutional attack on the law. It does not resolve the federal one.

What the Law Bans

Governor Pritzker signed the Protect Illinois Communities Act into law on January 10, 2023, following the Highland Park mass shooting. The Act prohibits the sale, purchase, manufacture, and delivery of firearms the statute defines as “assault weapons,” together with .50 BMG rifles, .50 BMG ammunition, large-capacity magazines, and rapid-fire conversion devices known as switches.¹

The statute reaches firearms in two ways. It names specific models directly, including the AR-15, AK-47, UZI pistol, and dozens of other rifles, pistols, and shotguns.² It also applies a features test: a semi-automatic rifle that accepts a detachable magazine and has at least one additional listed feature falls under the ban. Those features include a pistol grip, a folding or telescoping stock, a flash suppressor, a threaded barrel, a grenade launcher, a barrel shroud, or a buffer tube designed to allow shoulder firing.¹

A magazine is “large-capacity” if it holds more than 10 rounds for a long gun or more than 15 rounds for a handgun.¹ The named-model list is not exhaustive. Any firearm that matches the statutory definition is covered regardless of caliber or manufacturer.

Registering Firearms You Already Owned

The Act does not confiscate legally owned pre-ban firearms. It requires owners of newly restricted items to file a sworn endorsement affidavit through their Firearm Owner’s Identification (FOID) card account, which links each restricted item to a specific cardholder. The original filing deadline was January 1, 2024.¹ Large-capacity magazines are subject to the same geographic possession rules as banned firearms but do not require a separate affidavit.

Filing Late

The FOID portal remains open for endorsement affidavit submissions. The Illinois State Police have stated there are no separate fines specifically for filing late, but they warn that a local jurisdiction may treat a late affidavit as invalid.¹ Possessing a regulated item without a filed affidavit is a violation of Illinois law regardless of when the item was acquired. Anyone who missed the deadline but still owns restricted items should file now rather than assume the passage of time has made the item legal.

Inherited Firearms

Heirs can receive banned firearms even if the original owner never filed an affidavit. If you inherit an assault weapon, .50 caliber rifle, or large-capacity magazine, you must have a FOID card and file an endorsement affidavit within 60 days of receiving the item. The Act defines “heir” broadly to include anyone entitled to the property through a will, trust, intestate succession, or any other legally recognized method.¹

Where You Can Have a Grandfathered Weapon

Filing an affidavit does not restore full possession rights. A registered assault weapon, .50 caliber rifle, or large-capacity magazine can only be kept or carried in a short list of places:

Property you own or immediately control.
Another person’s private property with the owner’s express permission, provided the property is not open to the public.
A licensed firearms dealer or gunsmith, for lawful repair.
A licensed firing range or sport shooting competition.
In transit directly between any of the above locations.

These location limits apply to every regulated item, including large-capacity magazines.¹ Taking a grandfathered firearm anywhere else, even with a current affidavit, is a violation of the Act.

Selling, Transferring, and Repairing

Once your affidavit is on file, you can transfer the registered weapon to only three types of recipients: a legal heir, an individual who resides in another state and will keep the weapon there, or a federally licensed firearms dealer.¹ Selling or giving a restricted weapon to an Illinois resident who is neither an heir nor an FFL is not allowed.

Repairs remain permitted. A licensed dealer or gunsmith can order the replacement parts needed to restore a weapon to working condition. Buying additional “assault weapon attachments” beyond what is needed for that repair is not allowed.¹

Penalties

Possessing a regulated item without a filed endorsement affidavit violates both the FOID Act and the Criminal Code of 2012. The Illinois State Police have confirmed that violators can be arrested and charged under 430 ILCS 65/14 and 720 ILCS 5/24-1.¹ Depending on the specific facts and the defendant’s history, charges range from misdemeanors to felonies. Selling, manufacturing, or delivering a banned weapon to a non-exempt person carries its own penalties under 720 ILCS 5/24-1.9.³

Switches sit in their own category because federal law reaches them independently. A switch or auto sear that converts a semi-automatic firearm into one that fires multiple rounds with a single trigger pull is classified as a machine gun under the National Firearms Act and the Gun Control Act. The federal definition covers any part “designed and intended solely and exclusively for use in converting a weapon into a machinegun.”⁴ Federal penalties for possessing an unregistered machine gun or conversion device reach up to 10 years in prison and a $10,000 fine.⁵ In one recent case, a man who shipped firearms with a switch installed received seven years in federal prison plus three years of supervised release.⁶ An Illinois resident caught with a switch can face state and federal prosecution at the same time.

Who Is Exempt

The Act exempts several categories of people from the possession and purchase restrictions. Peace officers as defined under Illinois law, qualified active law enforcement officers, and qualified retired law enforcement officers recognized under the federal Law Enforcement Officers Safety Act may all continue to possess the regulated items.³ Someone who loses that exempt status can still keep their weapons by filing an endorsement affidavit through the state portal as a civilian owner.¹

The Federal Case Still to Watch

The Illinois Supreme Court’s decision closed the state constitutional door, but a parallel set of federal lawsuits attacks the Act on Second Amendment grounds. In Barnett v. Raoul, the U.S. District Court for the Southern District of Illinois ruled on November 8, 2024 that the Act violates the Second Amendment and issued a permanent injunction blocking its enforcement.⁷

That injunction was stayed immediately so the state could appeal. The case, consolidated with related challenges, went to the U.S. Court of Appeals for the Seventh Circuit, where oral arguments were scheduled for September 22, 2025. In June 2025, the U.S. Supreme Court declined to take up challenges to assault weapons bans from other states, leaving those bans in place without indicating how it would eventually rule on the merits.

Until the Seventh Circuit rules and any further appeal is resolved, the Illinois law remains in force. Owners of covered firearms should treat the registration, possession, and transfer rules as fully operative, because that is what the state ruling and the current stay in the federal case together produce.

1
Illinois State Police. Assault Weapons – Illinois State Police
2
Illinois General Assembly. HB5855 – Protect Illinois Communities Act
3
Illinois General Assembly. Illinois Code 720 ILCS 5/24-1.9 – Manufacture, Possession, Delivery, Sale, and Purchase of Assault Weapons
4
Bureau of Alcohol, Tobacco, Firearms and Explosives. ATF Ruling 2006-2 – Classification of Devices That Increase Rate of Fire
5
Office of the Law Revision Counsel. 26 U.S. Code 5871 – Penalties
6
Bureau of Alcohol, Tobacco, Firearms and Explosives. Twin Falls Man Sentenced to Federal Prison for Providing Illegal Firearms, Including Glock Switches
7
U.S. Department of Justice. Barnett v. Raoul – District Court Opinion