Jeff Asher and Rob Arthur write:

After murders in the United States soared to more than 21,000 in 2020, researchers began searching for a definitive explanation why. Many factors may have contributed, such as a pandemic-driven loss of social programs and societal and policing changes after George Floyd’s murder. But one hypothesis is simpler, and perhaps has significant explanatory power: A massive increase in gun sales in early 2020 led to additional murders.

New data from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) suggest that that indeed may have been the case. According to the data, newly purchased weapons found their way into crimes much more quickly and often last year than in prior years. That seems to point to a definitive conclusion—that new guns led to more murders—but the data set cannot prove that just yet.

The ATF data are the result of tracing nearly 400,000 firearms in 2020. According to the bureau, firearms are traced only “at the request of a law enforcement agency engaged in a bona fide criminal investigation where a firearm has been used or is suspected to have been used in a crime.” Not all guns recovered by law enforcement are traced, and many guns that are used in crimes are never recovered by law enforcement to begin with. But the ATF’s data are the most robust source available for evaluating the increased use of firearms in the United States in 2020.

What’s most startling in these new data is the degree to which firearms purchased in 2020 featured in crimes committed in 2020. The ATF’s data set includes a measure known as the “time to crime” of each gun traced—the time from when a firearm was legally purchased to when it was recovered after a crime. On this metric, an enormous shift is apparent: The number of traced guns whose time to crime was a year or more increased by less than 1 percent in 2020 compared with 2019, but the number of guns whose time to crime was six months or less increased by 90 percent.

Prior years looked quite different. [Continue reading…]