HARRISBURG — A Philadelphia ordinance that requires gun owners to tell police when a firearm has been lost or stolen was ruled illegal Monday by a Commonwealth Court panel, with one of the judges who voted to throw out the law lamenting that their ruling would put people’s lives at risk.

Philadelphia officials on Monday vowed to appeal the ruling to the state’s Supreme Court.

“The city is disappointed with the Commonwealth Court’s decision today as we maintain that our lost and stolen ordinance is legal. We agree with [Senior Judge Bonnie Brigance Leadbetter] that this case is ripe for the Supreme Court’s review given the plain language of the law; we plan to appeal this ruling,” city spokesperson Kevin Lessard said.

“The decision released today by the Commonwealth Court concerning the city’s lost or stolen handgun reporting ordinance was not unexpected. We always expected we would be arguing the case for Philadelphia’s right to enact and enforce its own lost or stolen gun law in the state Supreme Court, and that’s where this case is now headed,” City Council President Darrell Clarke said.

Philadelphia District Attorney Larry Krasner supports the city’s position on the reporting law, said Jane Roh, his spokesperson.

A three-judge panel ruled unanimously against the city law and issued a permanent injunction, saying the state Uniform Firearms Act preempts it.

The Philadelphia Police Department had sought a $2,000 fine against a man charged with violating the lost-and-stolen reporting mandate.

The defendant had pleaded guilty in January 2019 to other firearms offenses, telling a city judge he had been the straw purchaser of six guns. At that hearing, the judge had denied his request for an injunction against the Philadelphia lost-and-stolen firearms ordinance.

The judges cited a 1996 state Supreme Court decision that said assault weapons restrictions in Philadelphia and Pittsburgh were not allowed because the Uniform Firearms Act put authority to regulate firearms in the hands of the state Legislature.

Judge Leadbetter urged the Pennsylvania Supreme Court to reconsider that 1996 legal standard and to allow local restrictions “narrowly tailored to local necessities.”

“The overwhelming blight of gun violence occurring in the City of Philadelphia, of which I believe we can take judicial notice, and the policy issues argued by the city in the case before us, call for a recognition that local conditions may well justify more severe restrictions than are necessary statewide," Leadbetter wrote.

She said it violates the fundamental right to life and liberty when children can't walk on a street near their homes without the risk of being shot.

“It is neither just to impose unnecessarily harsh limits in communities where they are not required nor consistent with simple humanity to deny basic safety regulations to citizens who desperately need them,” Leadbetter wrote. She and both of the other judges who heard the appeal, Patricia McCullough and Anne Covey, were elected as Republicans.

City officials praised Leadbetter’s statement.

“Mayor Kenney completely agrees with the sentiment raised by Judge Leadbetter in her concurrence, where she notes that the gun violence experienced in the city of Philadelphia justifies stronger gun safety laws than may be necessary statewide and that we should not deny basic safety to our residents when they desperately need it,” Lessard said.

Most proposals to regulate guns have gone nowhere in the GOP-majority Legislature, and Democratic Gov. Tom Wolf has vetoed universal concealed carry and other Republican efforts to loosen firearms regulations.

Earlier this month, Wolf rejected a bill that would have helped gun owners and gun-rights groups seek civil damages from governmental bodies that pass firearms restrictions.

When a law was enacted in October 2018 to require those convicted of misdemeanor crimes of domestic violence or subject to protective orders to give up their guns within 24 hours, it was considered to be the first antiviolence legislation in the state in more than a decade to deal directly with guns.

Staff writer Mensah M. Dean contributed to this article.