Every year the Supreme Court refuses to hear thousands of cases. A denial of certiorari does not mean the Court agrees with the lower court decision. So most cert denials go unnoticed.
That said, many eyebrows were raised for many reasons when the Court denied cert in Friedman v. City of Highland Park. The issue in the case was whether the City of Highland Park could ban assault weapons and large capacity magazines.
In District of Columbia v. Heller (2008), the Court ruled that the Second Amendment provides individual the right to possess a firearm to use for lawful purposes, including for self-defense in the home. Many questions remain after Heller including whether the right to possess a gun extends outside the home and which types of guns are protected. Highland Park raised the latter question squarely.
The lower court upheld Highland Park’s ban. So, practically speaking, cities and states in the Seventh Circuit (Illinois, Indiana, and Wisconsin) may adopt similar bans without worrying about federal constitutional problems. In Fyock v. Sunnyvale the Ninth Circuit (Alaska, Arizona, California, Hawaii, Idaho, Montana, Nevada, Oregon, and Washington) also recently upheld an identical ban on assault weapons and large capacity magazines.
Justices Thomas and Scalia dissented from the denial of certiorari, which is fairly rare. The opined that the Seventh Circuit misread Heller to only forbid total bans on handguns when Heller only refuses to protect “those weapons not typically possessed by law-abiding citizens for lawful purposes.” According to Justices Thomas and Scalia, the overwhelming majority of the five million Americans who own assault-rifle-style semiautomatic firearms use them for lawful purposes.
The Court repeatedly postponed making a decision about granting or denying this case which indicates it was taking a close look at it. The denial came on the Monday following the San Bernardino shooting (but given that a dissent from the denial of certiorari was filed, it is clear the Court decided a while ago to deny cert).
So why did the Court ultimately refuse to take the case? The Court doesn’t explain its reasons for denying cert. Perhaps it is waiting for clearer disagreement from the federal circuit courts of appeals about this issue or it may want to first decide whether the right to possess a gun extends outside the home.