In 2021, things started to change. The country was experiencing a surge of deadly violence, with homicides up more than a third since 2019, and the administration of President Joe Biden was desperate to reverse the trend. For years, data had shown that a large share of guns used in shootings came from a small fraction of dealers, and that guns that were trafficked — sold by stores to straw purchasers (people other than the intended users) or resold on the street — were far more likely to be used in shootings.
Acting on this data, the administration in June 2021 announced what became known as “zero tolerance”: Dealers found to be willfully violating the law would lose their licenses, period. Revocations spiked, from fewer than 50 in 2019, 2020 and 2021 to a record 181 in 2023.
Also in 2021, Biden’s attorney general, Merrick Garland, started urging federal prosecutors to prioritize gun violence. A year later, Congress passed a law that added a firearms trafficking conspiracy charge to the federal criminal code, a crucial new tool for prosecutors.
After 2021, the homicide rate started falling, which criminologists attributed to several factors, including repair of the social fabric since the coronavirus pandemic and a closing of the breach in police-community relations that followed the 2020 murder of George Floyd. One other factor got less attention: the clampdown on the illegal flow of firearms.
The Biden administration struggled to broadcast its gains on public safety, and Donald Trump won election in 2024 partly by vowing to restore order. By the time Trump reentered the White House, Mitchem had risen to associate assistant director for industry operations, overseeing inspectors across the country. “We were making incredible progress on trafficking, on violent crime,” she said late last year.
But the Trump administration, driven both by gun-lobby advocacy and its own political priorities, quickly set about undoing much of its predecessor’s moves to combat gun violence. It repealed the zero-tolerance policy, going so far as to invite revoked dealers to reapply for new licenses. It shifted hundreds of ATF agents to immigration work. And it scaled back on prosecutions for gun trafficking. The White House declined to comment, referring questions to the ATF and the Department of Justice.
The homicide rate fell further last year, but criminologists warn against complacency, because the illicit gun trade is a classic pipeline problem: The harm can take a while to make itself felt. Research has found that the typical “time to crime” for trafficked firearms ranges up to about three years, which means that any positive lag of the anti-trafficking efforts of the Biden years would still be in effect now, with any negative effects of the Trump pullback lying in the years to come.