A federal judge upheld Colorado’s rule that mandates buyers must be at least 21 to purchase firearms, following a lawsuit from Rocky Mountain Gun Owners and two individuals targeting Democratic Governor Jared Polis.

Chief U.S. District Judge Philip A. Brimmer sided with the U.S. Court of Appeals for the 10th Circuit, stating that age-based purchase requirements aren’t covered by the Second Amendment’s rights to keep and bear arms. According to the 10th Circuit and Brimmer, these requirements are part of a “safe harbor” exclusion, thus not subject to constitutional protection.

Colorado’s age restriction for firearm purchases includes exceptions for U.S. Military members and peace officers. These exceptions apply only if the individual is purchasing while on duty and “in accordance with the policies” of their designated agency.

A customer looks over weapons for sale at the Pony Express Firearms shop in Parker, Colorado, on Dec. 7, 2015. (Reuters/Rick Wilking)

The decision in Colorado comes in contrast to one issued by the Supreme Court in 2022 in which justices determined that New York issued unconstitutional requirements for carrying a concealed weapon in public. Then-President Joe Biden said he was “deeply disappointed” by the ruling in New York State Rifle & Pistol Association v. Bruen. He said that SCOTUS had “chosen to strike down New York’s long-established authority to protect its citizens.”

“This ruling contradicts both common sense and the Constitution, and should deeply trouble us all,” Biden said in a statement at the time. He went on to reaffirm his commitment to reducing gun violence and making communities safer.

Brimmer is also going against a decision made by the New Orleans-based U.S. Court of Appeals for the 5th Circuit, which struck down a federal restriction banning the sale of firearms to anyone below the age of 21. That court held that those aged 18 to 20 are protected under the Second Amendment, according to The Trace, an organization of journalists who report on gun violence in the U.S.

A participant uses a handgun during a training session at a shooting range in Pompano Beach, Florida, on Oct. 25, 2023. (Marie Uzcategui/Bloomberg via Getty Images)

“The federal government has presented scant evidence that eighteen-to-twenty-year-olds’ firearm rights during the founding-era were restricted in a similar manner to the contemporary federal handgun purchase ban,” Judge Edith H. Jones wrote in the opinion.

Several states, including New York, Massachusetts, California, Florida, Illinois, Delaware and Vermont have raised the age for purchasing firearms, according to the Everytown for Gun Safety Support Fund. While some states have limited the age restrictions to handgun purchases, others have applied the restriction to any kind of firearm.