Loopholes and missing data: The gaps in the background check system

The time constraints placed on investigations make the system even more vulnerable to error. The biggest problem with NICS, in the eyes of its critics, is the so-called “Charleston loophole,” which permits buyers to pick up their weapons after three business days even if they have not yet been fully vetted, a scenario that can occur when a potential problem is identified that requires a follow-up investigation.

The 72-hour rule, inserted at the behest of Republican lawmakers in negotiations over the Brady Bill three decades ago, played a direct role in one of the deadliest racial rampages in American history. A white supremacist who killed nine people at a predominantly Black church in Charleston, S.C., in 2015 was allowed to pick up his gun after three business days had elapsed even though a full review had not been completed.

It later emerged that the gunman should have been barred from buying a firearm because he had previously admitted to police to having been in possession of a controlled substance. But confusion over local law enforcement records prevented authorities from spotting the issue within the designated time frame.

It is not known how many crimes have been committed by buyers who were allowed to retrieve their guns after three days with still-incomplete background checks — but between 5,000 and 6,500 weapons a year are confiscated from people who were later determined to be disqualified, according to the F.B.I.’s 2021 NICS operations report.