Amid calls for universal background checks, little evidence they stop mass shootings

In the wake of the recent deadly mass shooting in Boulder, Colo., gun control supporters have renewed demands for universal gun background checks throughout the United States, despite years of data indicating that nearly all major mass shooting events would be unaffected by such policies. 

The Boulder shooting came on the heels of last week's Atlanta mass shooting. Together, the two incidents claimed a combined 18 lives. 

President Joe Biden himself called on lawmakers to "close the loopholes in our background check system," including what's popularly known as the "Charleston loophole," through which individuals can purchase a gun without a background check if the FBI fails to process the check within three days of receiving it. 

Biden explicitly asked the Senate to approve two recent background check bills passed by the house. One, H.R. 8, largely "prohibits a firearm transfer between private parties" absent a background check. The other, H.R. 1446, would address the so-called "Charleston loophole" by broadening the waiting time from three days to 20. 

Most major mass shooters passed background checks

Yet in spite of perennial demands from gun control advocates for an expanded background check system throughout the United States, a review of major mass shooting incidents over the last several years indicates that such policies would have very minimal effect on such tragedies. 

A lengthy review of nearly 20 mass shootings by the New York Times found that "a vast majority of guns used [in those shootings] were bought legally and with a federal background check."

Only a few of the shooters on that list obtained their firearms without passing federal background checks. The white supremacist shooter who murdered nine people at a black church in Charleston, S.C. in 2015 purchased his gun after the FBI failed to conduct his background check in a timely fashion (the "Charleston loophole" gets its name from that incident). A shooter who committed mass murder in Binghamton, N.Y. in 2009 obtained his gun the same way. 

In one case — that of the Sandy Hook Elementary School massacre in 2012 — the shooter obtained his weapons by killing his mother and stealing her guns. Those firearms had been purchased legally by the shooter's mother.