Gun Violence Prevention Measures

On Tuesday, June 7, 2022, City Council passed six gun violence prevention measures designed to keep the community safer from gun violence.

August 30, 2022 Update

  • The ban on assault weapons and large-capacity magazines has been paused to allow for more legal coordination.
  • All other measures, including the ban on trigger activators, remain in effect.

Overview of Measures Passed June 7, 2022

Boulder’s measures achieve the following:

  • Banning assault weapons, large-capacity magazines, and trigger activators such as bump stocks, similar to the laws passed in Boulder in 2018. The previous ban was challenged in court because of the state pre-emption statute at the time.
  • Banning ‘ghost’ guns, as Denver did earlier this year. The term “ghost guns” refers to firearms without serial numbers that are often built from 3-D printers or kits and are therefore nearly impossible to trace.
  • Raising the age limit for purchasing firearms from 18 to 21 and/or updating language to demonstrate this intent. Evidence shows that individuals in the 18 to 21 age range are at a higher risk of committing violence.
  • Instituting a 10-day waiting period for firearm purchases. This is designed to prevent purchase of firearms on impulse for immediate use.
  • Prohibition on open carry in public places. The open carry of firearms allows intimidation of peaceful protesters and voters. It can also help enable persons intent on gun rampages avoid police in the time leading up to the moment of shooting.
  • Disallowing carry in “sensitive” areas. These areas would include public buildings, polling places and ballot counting centers, banks, theaters, courthouses, hospitals, and other sensitive locations.
  • Requiring firearm sellers to post a health warning on premises. Signage would warn of the increased risks associated with firearms ownership, including suicide, death during domestic disputes, and unintended deaths of children or other family members.


In response to the tragedy at Marjorie Stoneman Douglas High School in Parkland, Florida on February 14, 2018, City Council passed two ordinances that, among other things, banned possession of most assault weapons within city limits, banned magazines capable of holding more than 10 rounds of ammunition, and raised the legal age to possess firearms from 18 to 21. Litigation ensued, and on March 12, 2021, the Boulder County District Court ruled that the city’s assault weapons ban, and large-capacity magazine restrictions were void as preempted by state law.

On March 22, 2021, a shooter armed with a semi-automatic Ruger AR-556 pistol killed 10 people at the King Soopers on Table Mesa Drive in Boulder. In response to the district court ruling and the shooting, the state legislature repealed the state’s preemption statute. State law now expressly allows municipalities to enact firearms regulations stricter than those found in state statutes. The purpose of the ordinances is to enact new regulations in compliance with the state statute and to expand Boulder’s efforts to prevent gun violence.

Assault weapons are semi-automatic firearms designed with military features to allow rapid spray firing for the quick and efficient killing of humans. An automatic weapon is one that fires multiple rounds with a single pull of the trigger. A semi-automatic weapon fires only one round per trigger pull, but automatically loads a round after each shot.

Assault weapons are civilian versions of military weapons. For example, the difference between a AR-15 and its military counterpart the M-16, is that the M-16 is an automatic weapon while the AR-15 is a semi-automatic weapon. The AR-15 requires the shooter to pull the trigger for each round that is fired. Fully automatic weapons are banned by federal law.

The automatic firing mechanism does not present a significant increase in the lethality of the M-16 when compared to the AR-15. The military trains its personnel to use repeated single shots, which are more accurate. Military training is for personnel to shoot 12 to 15 rounds per minute or one round every four to five seconds.

Assault weapons are deadly because they allow a shooter to fire a high number of rounds quickly, under control. The features that create this lethality are the ability to accept magazines holding as many as 100 rounds. These magazines are designed to be replaced quickly, which increases the number of rounds that can be fired. In addition, assault weapons are designed to maintain stability while firing. A rifle fired from the shoulder recoils and must be brought down and onto a target before another round can be fired.

Assault weapons have features such as pistol grips or thumb-hole grips, a forward grip or a barrel shroud, which allow for greater control of the weapon allowing it to be kept pointed at a target while being fired. The pistol grip or thumb-hole grip allows for greater control with the trigger hand. The forward grip or barrel shroud, which is a fitting on the barrel that protects the shooter’s hand from the heated barrel allowing the shooter to grip the barrel, both allow for better control with the non-trigger hand. The combination of high-capacity magazines and better control can make semi-automatic assault weapons as lethal as the military counterparts.

Ordinances 8528 and 8529 are meant to address the problem of impulsive crimes or suicides made possible by easy access to firearms. Ordinance 8528 requires gun dealers to post signage in English and Spanish regarding the dangers of firearms possession. Ordinance 8259 requires a 10-day waiting period after a vendor initiates a background check before a purchaser can take delivery of a firearm.

Community Sustainability Assessments and Impacts

  • Economic – There are two businesses in Boulder that sell the products that council is considering for a ban. Tax revenue from these businesses will likely decrease, although the true cost of gun violence may exceed the economic impact of gun sales and manufacturing.
  • Environmental – None identified.
  • Social – Public safety is among the city’s highest priorities. Any reduction or prevention of gun violence will have a positive social impact.

Other Impacts

  • Fiscal – All work for drafting will be performed within existing department budgets. The final ordinances may require additional funding to implement.
  • Staff time – Enforcement of these new ordinances will require police staff time.