U.S. Rep. Jason Crow is reintroducing legislation to set new legal standards and certification requirements for licensed gun dealers in an effort to prevent firearms from being diverted into illegal markets, the Centennial Democrat said Friday.

H.R. 5678, dubbed the Firearm Retailer Code of Conduct Act, would establish biennial training requirements to help gun dealers and their employees identify and prevent so-called straw purchases, where a customer buys a gun for someone else.

The bill would set a requirement to instruct dealers that they’re supposed to refuse to sell firearms to straw purchasers, gun traffickers, intoxicated people and those at risk of harming themselves or others. It would also create a federal legal standard for what constitutes a straw purchase, require that dealers store their merchandise securely and mandate that dealers carry business and liability insurance.

“I imagine many of you are probably thinking to yourself, ‘I can’t believe some of this stuff isn’t already law and that this isn’t already there,'” said Crow in a remote press conference. “Because it just seems such common sense to most folks. But unfortunately, we work in a space here with the gun lobby that is resistant to very basic standards and protections for folks, but that’s why we’re working to change it.”

Maisha Fields, the daughter of state Sen. Rhonda Fields, D-Aurora, and the vice president of organizing at Brady, a national nonprofit that advocates for gun safety, said data shows that 90% of guns used in crimes come from just 5% of gun dealers.

“We know that addressing the flow of gun violence from that 5% can and will save lives,” she said. “The overwhelming majority of gun dealers take every effort to fulfill their responsibility to sell these weapons responsibly. But under current law, gun dealers and their employees are not required to receive any training – no training at all – to sell a gun to a customer.”

Fields, whose brother Javad Marshall-Fields and his fiancé Vivian Wolfe were gunned down in Aurora in 2005, added: “This is a crisis, and Rep. Crow’s bill will help to remedy the supply of the weapons fueling this epidemic. In no uncertain terms, this bill will save lives.”

Taylor Rhodes, executive director of Rocky Mountain Gun Owners, which bills itself as the state’s “no compromise” gun rights group, said in a statement to Colorado Politics that Crow’s bill is both unnecessary and goes too far.

“This is another example of government overreach by the radical anti-gun Left, without understanding the community of gun owners and firearms dealers,” Rhodes said. “Many of the items detailed in this bill are already standard practice in gun shops and ranges across our state. I would encourage Rep. Crow to visit a gun shop in his district; maybe then he would realize he is trying to solve a problem that doesn’t exist.”

The bill had 19 co-sponsors on Friday morning, all House Democrats, including U.S. Rep. Joe Neguse of Lafayette. Last week, Neguse and Crow called on Democratic leadership to preserve $5 billion in funding for community violence intervention programs in the massive budget reconciliation bill currently under negotiation.

UPDATE: This story has been updated to include a comment from Rocky Mountain Gun Owners executive director Taylor Rhodes.