The National Association for Gun Rights, the Rocky Mountain Gun Owners, and three local gun owners are challenging Colorado's new "ghost gun" ban law, The Denver Post reported.
The federal lawsuit, filed against Gov. Jared Polis, contests the ban's alignment with the Second Amendment.
Ghost guns are unregulated, unserialized, and untraceable firearms.
"This law is an outright assault on the constitutional rights of peaceable Coloradans," Taylor D. Rhodes, the executive director of the Rocky Mountain Gun Owners, told Fox News. "It's not just an overreach; it's a direct defiance to our Second Amendment freedoms."
The law, effective as of Monday, targets unserialized firearms and parts, a move the plaintiffs deem unconstitutional.