An El Paso County resident and several gun rights groups have filed a lawsuit against Department of Revenue Executive Director Heidi Humphreys and El Paso County District Attorney Michael Allen over the state’s firearms and ammunition excise tax, which went into effect April 1. 

Known as Proposition KK, the 6.5% excise tax was approved by voters in November’s election. Proceeds from the taxes collected will be used to fund support services for crime victims, veterans, and youth, as well as school safety programs. 

The complaint, filed by Zachary Langston and groups, including the National Rifle Association, Colorado State Shooting Association, and Magnum Shooting Center, argues the tax is unconstitutional under the Supreme Court’s 2022 Bruen decision, in which justices found that in order for a law regarding firearms to be constitutional, it must be supported by “tradition or historical precedent.”

“This infringement-by-taxation scheme is unsupported by this country’s history and tradition of firearm regulation,” the complaint stated. “The only rule that accords with Supreme Court precedent and common sense is that the exercise of protected constitutional rights cannot be singled out for special taxation.”

Gun rights groups have also filed a lawsuit in the San Diego Superior Court against California’s 11% firearms and ammunitions excise tax, which went into effect last July.