The White House on Thursday honored "the will of the vast majority of the American people," one Democratic lawmaker said, as President Joe Biden announced a final rule closing a loophole that has left tens of thousands of firearms dealers able to sell guns without running background checks on purchasers.

The Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) will require anyone "engaged in the business" of selling firearms for a profit to register as a federally licensed firearms dealer, which will require them to conduct background criminal and mental health checks on their customers.

Previously, dealers who sell guns online, at gun shows, and through private transactions had been required to register with the federal government only if their gun sales were the primary provider of their livelihood—the so-called "gun show loophole," which allowed roughly 23,000 private sellers in 29 states to conduct their business without determining if buyers had a history of abuse, violence, or mental health struggles.

Sellers who fail to register will risk being fined $250,000 and a potential prison sentence of up to five years.

The ATF released firearms trafficking data last week showing that four in 10 illegal gun cases tracked by the agency between 2017-21 involved sales through private dealers, which account for 40% of all gun sales in the U.S. according to some estimates.

"This rule will save lives by ensuring those who engage in the business of selling firearms are taking the necessary precautions we require of all other licensed gun sellers."

The gunman in a 2019 mass shooting in Midland, Texas, obtained his AR-style rifle through a private sale, allowing him to kill seven people. He had previously been blocked from buying a gun in 2014 due to a background check that showed a court had determined he had a mental illness.

A 2022 shooting at a high school in St. Louis was also made possible by a private online sale; the gunman had struggled with severe mental health issues and had been automatically rejected by the federal background check system when he tried to purchase a gun 16 days before the attack. He then purchased a gun without undergoing a background check, and later killed a 15-year-old student as well as a teacher.

"To be clear, that 'gun show loophole' has been a death sentence for countless Americans, and that will change with this action," said Kris Brown, president of the gun violence prevention group Brady. "This rule will save lives by ensuring those who engage in the business of selling firearms are taking the necessary precautions we require of all other licensed gun sellers. In doing so, we can mitigate the proliferation of firearms in our communities and keep weapons out of the hands of those most at risk of harm."

"I am elated that President Biden continues to deliver on his promise to represent the will of the people and make progress to free America from gun violence," she added. "I urge Congress to follow suit and pass universal background checks without delay."

Brown noted that 90% of Americans support universal background checks for gun purchases, and that the new rule is the direct result of the Bipartisan Safer Communities Act, which was passed in 2022.

U.S. Sen. Chris Murphy (D-Conn.) called the rule "the most impactful change made possible by the 2022 gun safety bill."

March for Our Lives, the advocacy group established by young survivors of the 2018 Parkland, Florida school shooting, credited gun control supporters who submitted public comments supporting the new rule.

"For years, this glaring loophole let people who shouldn't have access to a gun otherwise slip through the cracks to get a deadly weapon and cause harm," said the group. "Not anymore."

House Democratic Whip Katherine Clark (Mass.) called on Congress to build on the Biden administration's progress "by fully closing the boyfriend loophole, enacting a nationwide red flag law, getting high-capacity magazines off the street, and reenacting the federal assault weapons ban."

"Thanks to the non-stop advocacy of survivors across the country, the leadership of the Biden-Harris administration, and the persistence of Democrats in Congress," she said, "America has taken the greatest strides against gun violence that we've seen in three decades."

Republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).