Justice Department Expands Lawsuit Against D.C. Gun Regulations

The Justice Department’s Civil Rights Division has updated its lawsuit against Washington, D.C., to address not only the district’s prohibition on AR-15 rifles but also its ban on suppressors, which are devices used to muffle gun sounds.

Initially reported by Breitbart News in December 2025, the lawsuit focused on the district’s stringent regulations concerning AR-15s. The Justice Department contended that the laws regarding “assault weapons” hinge primarily on their appearance rather than actual functionality.

On May 14, 2026, the complaint was amended to include the suppressor ban as well, with the Department arguing that D.C. Code § 22–4514(a) unjustly prevents the use of these devices, which law-abiding Americans often utilize. The assertion is that such a blanket prohibition infringes upon Second Amendment rights.

While suppressors are under the National Firearms Act’s regulations, the lawsuit highlights that D.C. takes this further by imposing an outright ban.

The Justice Department believes that this ban is unlikely to hold up legally. They cited a precedent indicating that the Second Amendment applies to all carryable weapons, including those developed after its inception; thus, suppressors are likely to be regarded as protected items.

Additionally, the Department stated that the D.C. government cannot prove this law’s constitutionality, arguing there’s no historical basis for prohibiting commonly used weapons.

Breitbart News also noted that on May 5, 2026, the Justice Department filed a similar lawsuit against Denver’s “assault weapons” ban, followed by another the next day regarding Colorado’s restriction on magazines holding 15 or more rounds.