Colorado Gov. Jared Polis, center, hands a pen he used to sign Senate Bill 3 into law to state Sen. Tom Sullivan on the left. Credit- Colorado Sun

Colorado Gov. Jared Polis recently signed a bill requiring people to pass a background check and complete a state-sanctioned safety course to buy most semi automatic guns with detachable magazines. This move now sees the Centennial State with one of the most restrictive gun laws in the country which will come into full effect in August 2026.

It’s no secret that Colorado has seen some of the country’s worst mass shootings — including the 2022 killings at the LGBTQ+ nightspot Club Q in Colorado Springs and the 1999 Columbine High School massacre, just to name a few.

Previous attempts at securing an all-out ban on certain semi automatic guns, as has been done in other Democratic states like New York and California, floundered in Colorado where many including the governor have something of a libertarian streak.

The proposal was watered down from a ban on the manufacture and sale of semi automatics with detachable magazines, including rifles and some pistols. Proponents argued that allowing only permanently attached magazines would force a would-be shooter to reload bullet by bullet.

Under the new law, it is illegal to buy, sell and make most semi-automatic firearms without background checks and training. Individuals would need to pass a background check and receive an eligibility card from their county sheriff, who could deny it if he or she believed the person was a danger.

Those eligible for training would need to pass a 12-hour safety course certified by Colorado Parks and Wildlife unless they have completed hunters’ training, and then it would be 4 hours.

Colorado Gov. Jared Polis signs Senate Bill 25-3, a gun safety measure at the Colorado Capitol. Credit-cpr.org

Opposition to the law has been fierce though, as the Colorado State Shooting Association plans to sue to block the law. The group says the expense associated with obtaining a permit, training and background checks infringes on people’s constitutional right to keep and bear arms.

Republicans in the legislature announced days after the gun law was signed that they have asked the federal government to investigate whether it infringes on the U.S. Constitution.

House Republicans argue it is unconstitutional because it undermines the Second Amendment. In their letter, they called the law’s passage “an emergency” for Coloradans’ self-defense and that they “are calling on the federal administration to aid our efforts in challenging the constitutionality” of the measure.

Democrats on the other hand say they aren’t fussed and that they are confident the law will stand up to any test because they consulted regularly with the state’s attorney general while crafting the bill.

Other critics have argued that the slew of firearms restrictions approved by the Democratic-controlled legislature haven’t stopped gun violence, while at the same time making it difficult for Coloradans to defend themselves against criminals who don’t adhere to state gun laws.

Bill sponsor and state Sen. Tom Sullivan, a Democrat representing Arapahoe and Douglas counties whose son, Alex, was killed in the 2013 mass shooting at a movie theater in Aurora has said that the measure is “just the next step they have undertaken on that effort”.

Rifles on display at a gun store in downtown Denver. Credit-cpr.org

The counties he represents are home to Aurora where the 2012 theater mass shooting took place that killed his son Alex and 11 other people, injuring 70. Sullivan believes his son could have possibly gotten to safety if the gunman had not used a rapid-fire assault weapon.

The violence was a result of the extraordinary firepower that comes from using multiple magazines, which, in scenarios across the country, has led to mass shootings and a challenge for law enforcement. Gunfire was so intense that victims had no time to take relatively easy steps – to fall to the floor, to run for cover around a corner – to avoid being shot.

Right now, while majority of Coloradans are quite pleased with the measures taken to curb gun violence, everyone knows that opposition to the bill is far from over, and with the Trump administration’s current fixation on all things Colorado coupled with the propensity to dabble into the grey, the whole of Colorado and America await the verdict of the U.S. attorney general.