A federal judge has overturned the District’s signature gun law, and while the city gears up to fight the ruling, D.C. police now say that they will not arrest people carrying registered handguns on the streets. Before you walk out your front door with your gun in your hand — or you start keeping a wary eye out for guns in your neighborhood — here’s what you need to know.

What was the law that was overturned by this decision?

The law forbade carrying handguns in public places. A little bit of history: All the way from 1976, shortly after the District gained home rule, until 2008, handguns were banned entirely in the District. Then in a case called District of Columbia v. Heller, the Supreme Court ruled that individuals had a right to own handguns. The District came up with a new law that said people could own the guns, but not carry them in public. Now a federal judge has ruled that the ban on carrying handguns is also unconstitutional.

I’m a District resident. Can I carry a gun in public now?

If you own a registered gun, you can carry it. But that’s not as likely in D.C. as in most states because existing D.C. laws makes it very hard for residents to obtain gun ownership licenses. The process is involved, time-consuming and expensive. Police officials said that since 2008, there have been 3,078 handguns registered in the District.

I live in another state, where I can legally carry a gun. Can I bring it to Washington?

Yes, now you can. In a memo to all officers on Sunday night, the D.C. police department announced that it would not arrest people who are following the laws of their own state if they bring a gun to the District. That means that if you live in a state where you don’t need a license to carry a gun, now you don’t need one to carry that gun in Washington either. D.C. Mayor Vincent Gray (D) has asked non-residents not to bring guns to the city, but right now, there isn’t much he can do about it.

Are there places in the city where handguns are still banned?

Yes. Guns remain forbidden on District government property, including schools, parks, recreation centers and office buildings. At the John A. Wilson Building, the District’s city hall, security guards on Monday continued to screen visitors with X-ray machines and metal detectors.

Federal law prohibits firearms on the grounds of the Capitol. And private property owners, according to city law, may still ban guns from their property.

What can the city do now?

The mayor and several D.C. Council members have made it clear that they find the ruling worrisome, and they intend to do what they can to keep guns off the streets. That may mean writing new legislation. But for now, the focus is on the courts. The city attorney general’s office has asked the judge who decided the case to stay his ruling, so that the city’s gun laws would remain intact until a possible appeal is considered.

Mike DeBonis and Clarence Williams contributed to this report.

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