After a domestic terrorist with several firearms, including an AR-15 assault rifle, murdered 11 worshipers in the Tree of Life Synagogue in Pittsburgh in October, Mayor Jim Kenney released a statement saying: “We stand ready to help Pittsburgh in any way we can.”

It’s time to make good on that promise by enacting local gun-control ordinances against state law and marching to court with Pittsburgh.

In response to the massacre, Pittsburgh Mayor Bill Peduto and Pittsburgh Council members cosponsored a package of gun-control bills. Measures included in the bills are: a ban on assault weapons within city limits, a ban on bump-stocks, and a move that would allow courts to confiscate firearms from people who are a threat to themselves or others. Also in the package is funding for community organizations working to prevent gun violence.

There is only one problem — under Pennsylvania state law no county or city is allowed to regulate the lawful ownership, possession, or transfer of firearms. Gun-control opponents in Pittsburgh have been calling for Peduto’s impeachment. Some met with Allegheny County’s district attorney to seek criminal charges against the mayor. Peduto’s response: “Arrest me. Sue me. Impeach me. I was elected to protect my constituents and that is exactly what I will do.”

It seems unlikely that Peduto will be arrested. But it is likely that the city will be dragged to court over this law. It has happened before — with mixed results.

Philadelphia tried to ban assault weapons in the past. City Council passed an assault weapons ban in 1993 but the state responded by repealing the ban, and the Pa. Supreme Court upheld that repeal in 1996. The city passed a ban in 2007, which the court struck down twice — both in its first ruling and when the city appealed.

In 2015, the National Rifle Association sued both Philadelphia and Pittsburgh over ordinances that penalize gun owners if they fail to report when their gun goes missing. At the time, the ordinances were on the books but not enforced. The Pa. Supreme Court ruled that the state law that gave the NRA standing to sue was enacted in an unconstitutional manner. The lawsuit was dismissed in 2016. We have to wonder if part of that success was because the NRA went after more than one city.

Philadelphia should stand with Pittsburgh now.

Philadelphia is not afraid of implementing its own vision even when it goes against state or federal law. In the 1990s, Philadelphia authorized a syringe-exchange program to address the AIDS crisis in clear violation of federal law. Mayor Jim Kenney went head-to-head with the Justice Department in a lawsuit to protect Philadelphia “sanctuary city” status — and won. Most recently, the city has supported opening a supervised injection site, which the area’s U.S. attorney argues violates federal law.

City Council and the mayor should stand with Pittsburgh — that means enacting the same gun-control package that Pittsburgh is introducing and signing it into law. Even if becomes only a symbolic gesture, it sends a strong message that the state’s two biggest cities are committed to protecting the lives of their residents.