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A Colorado judge blocked Boulder from enforcing its two-year-old assault rifle ban on March 12, ruling it violated a 2003 state law prohibiting municipalities from enacting their own firearms regulations. Boulder city spokeswoman Shannon Aulabaugh said city attorneys would meet to decide on whether to appeal the ruling by Boulder County District Court Judge Andrew Hartman, The Denver Post reported March 18, but in the meantime, the Boulder Police Department wouldn't enforce the ban on AR-15-style rifles and large-capacity magazines.

The National Rifle Association celebrated the ruling last Tuesday, noting its supporting role in striking down the ban. A week later, a gunman opened fire in a Boulder supermarket, killing 10 people, including a Boulder Police officer.

Police have not yet publicly identified the suspected shooter or the type of weapon used. But "one senior law enforcement source told CNN the weapon used in the shooting was an AR-15-style rifle," CNN reports. Boulder enacted its ban in response to the mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, carried out — like many mass shootings — with an AR-15.