Federal judge upholds Colorado semiautomatic firearm law

A federal judge on Wednesday denied a request to block the enforcement of a Colorado law that mandates safety training and eligibility cards for the purchase of certain semiautomatic firearms. The ruling allows the state to continue implementing the regulations that took effect on Aug. 1, 2026.

Senior U.S. District Judge William Martinez issued the opinion, rejecting a lawsuit filed by six individuals and the Colorado State Shooting Association against Governor Jared Polis and Attorney General Philip Weiser. In his decision, Martinez stated that the plaintiffs failed to demonstrate a substantial likelihood of success on the merits of their Second Amendment challenge.

The law, known as SB25-3, requires buyers of specified semiautomatic rifles, shotguns with detachable magazines, or gas-operated semiautomatic handguns with detachable magazines to complete a state-certified safety course. Depending on their credentials, buyers must finish either a four-hour or 12-hour course and obtain an eligibility card from their county sheriff. The process includes a $52 fee paid to Colorado Parks and Wildlife, alongside potential local sheriff fees.

Under the statute, first-time violations are classified as a class 2 misdemeanor, while subsequent infractions are treated as a class 6 felony. The legislation does not apply to individuals who already owned these firearms prior to the Aug. 1, 2026, effective date.

In his ruling, Martinez noted that the plaintiffs were unlikely to suffer irreparable injury and concluded that the balance of the equities and public interest favored the state defendants.