The Supreme Court refuses to block an Illinois law banning some high-power semiautomatic weapons

The Supreme Court on Thursday declined to put on hold a new Illinois law that would ban high-power semiautomatic weapons like the one used in the mass killing of seven people at a 2022 parade in a Chicago suburb.

The justices did not comment in refusing an emergency appeal from a gun rights group and others.

The law prohibits the possession, manufacture or sale of semiautomatic rifles and high-capacity magazines. It takes effect Jan. 1.

Last month, a three-judge panel of the 7th District U.S. Court of Appeals voted 2-1 in favor of the law, refusing a request by gun rights groups to block it. The Illinois Supreme Court separately upheld the law on a 4-3 decision in August.

At least eight other states and the District of Columbia have some sort of prohibition on semiautomatic weapons, and several cases challenging those laws are making their way through the federal courts, relying at least in part on the Supreme Court's decision in 2022 that expanded gun rights.

The Protect Illinois Communities Act bans dozens of specific brands or types of rifles and handguns, including the popular AR-15, .50-caliber guns, attachments and rapid-firing devices. No rifle will be allowed to accommodate more than 10 rounds, with a 15-round limit for handguns.

Those who own such guns and accessories when the law was enacted have to register them, including serial numbers, with the Illinois State Police. That process began Oct. 1.