In District of Columbia v. Heller, the U.S. Supreme Court held that Washington, D.C.’s ban on handgun possession unconstitutionally infringed on Second Amendment rights. Yet a District law prohibiting — with few exceptions — ammunition in residents’ homes lingers on the books.

What good is the right to keep and bear arms for self-defense if you cannot have ammunition? How can residents look to the law to understand what conduct is — and is not — illegal? Should they follow the statutes? The court? Get confused and forgo their rights?

In Marbury v. Madison, Chief Justice John Marshall wrote that if a statute is “in opposition to the Constitution,” the Constitution “must govern.”

Following that principle, the criminal code reform commission established by the City Council has reviewed the district’s criminal laws and identified two statutes — Unlawful Possession of Ammunition (D.C. Code 7-2506.01) and Alteration of Identifying Marks of Weapons (D.C. Code 22-4512) — as being unconstitutional.

The commission’s findings rest on two cases in D.C. courts: Herrington v. United States and Reid v. United States.

In Herrington, the trial court had ruled that “all the government needs to prove to obtain [an unlawful possession of ammunition] conviction are ‘that the defendant possessed ammunition, and that he did so knowingly and intentionally.’” The D.C. Court of Appeals disagreed, writing, “a flat ban on the possession of handgun ammunition in the home is not just incompatible with the Second Amendment, but clearly so.”

Yet it ruled that the government may convict a defendant of unlawful possession of ammunition if it also proves beyond a reasonable doubt that he had not lawfully registered “a firearm of the same gauge or caliber as the ammunition he possesses.”

The commission’s report identifies the statute as unconstitutional but advises lawmakers to cure that by amending the law to incorporate the court’s ruling.

The second offense makes it a crime to alter or obliterate a firearm’s serial number. The commission’s report observes that the law also permits a jury “to infer that a person who possesses a weapon with obliterated markings is the same person who did, in fact, obliterate those markings.”

In Reid, the D.C. Court of Appeals recognized that individuals might unknowingly acquire weapons with previously obliterated markings, and that, therefore, the presumption of guilt in the statute is fundamentally unfair and violates due process.

Thirty-four years later, commissioners are just now advising lawmakers to bring the law up to date with the U.S. Constitution.

The commissioners give three reasons why lawmakers should no longer delay updating D.C. firearms laws:

1) to ensure respect for the people’s constitutional rights;

2) to “clarify to the general public what precisely constitutes” an offense; and

3) to “guide practitioners in the future.”

For the same reasons, other states should review their criminal codes to ensure that Second Amendment rights, and other constitutional provisions, are protected.

As the Supreme Court stated in McBoyle v. United States in 1931, and had recognized long before that, “fair warning should be given to the world in language that the common world will understand, of what the law intends to do if a certain line is passed. To make the warning fair, so far as possible the line should be clear.”

In Heller, the Court wrote that the Second Amendment bears no “secret or technical meanings that would not have been known to ordinary citizens in the founding generation.” In McDonald v. Chicago, the Court held that “the Second Amendment right, recognized in Heller, to keep and bear arms for the purpose of self-defense” applies to the states.

The D.C. Criminal Code Reform Commission represents a step in the right direction. It has provided a straightforward methodology for reviewing criminal laws in the interest of protecting constitutional rights. It is an approach that all cities and states should consider taking.