The Colorado Bureau of Investigation received and processed a record number of background check requests for gun purchases last month ahead of a new law taking effect Saturday prohibiting people from buying certain semiautomatic weapons without additional vetting and completing a safety course.
The agency, which added staff in anticipation of the surge, reported Monday that it received 59,452 background check requests in July, nearly triple the number of applications compared with the same period last year. In July 2025, CBI processed 20,172 gun background checks.
Since July 2013, Colorado law has required that anyone seeking to buy or receive a gun first go through a background check to ensure they don’t have a criminal history that would make them ineligible to purchase or possess a firearm.
And while the Colorado legislature has adopted many new gun laws since then, they didn’t generate a comparable surge in background checks.
On Saturday, Senate Bill 3 — passed by Democrats in the legislature in 2025 — took effect. It requires that people seeking to purchase many semiautomatic firearms with detachable magazines, namely rifles like the AR-15 and its long list of variants, go through more thorough vetting by their county’s sheriff, specifically a deeper background check, and complete a course before being eligible to buy the weapons.
The process can cost hundreds of dollars and the course, for those who haven’t already completed hunter safety training, takes two days.
The course was developed by Colorado Parks and Wildlife, which is taking a lead on implementing Senate Bill 3.
“This curriculum was developed by CPW and 11 volunteer verified firearms instructors from across the state with over 150 collective years of experience in firearms safety training,” CPW spokesperson Travis Duncan said in a written statement. “Courses will instruct students on general gun safety, which applies to all situations where a firearm is being handled, child safety and safe storage of firearms, basic handling of firearms, including specified semiautomatic firearms and ammunition magazines, firearm deaths associated with mental illness, extreme risk protection orders, and victim awareness and empathy along with other firearms safety-related topics.”
The law is one of the most stringent restrictions on gun ownership ever adopted in Colorado, if not the most stringent. State Sen. Tom Sullivan, a Centennial Democrat and lead sponsor of Senate Bill 3, said the measure is effectively a ban on what are commonly referred to assault weapons.
“In essence, we have it,” Sullivan said.
CBI Director Armando Saldate said his hope for July was to ensure that all firearms background checks be processed within 72 hours, which is also the waiting period in state law between when someone purchases a gun and can access it.
Saldate said his agency was able to hit that goal by shuffling staff to double the size of its background check unit and letting staff work from home and work overtime hours.
“We had to work night and day,” he said in an interview.