NPR has a piece that details the failure of the the National Instant Background Check System (NICS) to prevent mass shootings despite being touted at the time as a means to keep guns out of the hands of those who would do harm to others.

The National Instant Criminal Background Check System, or NICS, is all about saving lives and protecting people from harm—by not letting guns fall into the wrong hands. It also ensures the timely transfer of firearms to eligible gun buyers. Mandated by the Brady Handgun Violence Prevention Act of 1993 and launched by the FBI on November 30, 1998, NICS is used by Federal Firearms Licensees (FFLs) to instantly determine whether a prospective buyer is eligible to buy firearms. Before ringing up the sale, cashiers call in a check to the FBI or to other designated agencies to ensure that each customer does not have a criminal record or isn’t otherwise ineligible to make a purchase. More than 230 million such checks have been made, leading to more than 1.3 million denials.

NPR reports that as a practical matter, the law has been a failure.

"The weakness of the NICS system is talked about mostly in the wake of a tragic shooting, which happens more often than not," says Stephen Morris, a former FBI assistant director for the Criminal Justice Information Services Division, which oversees NICS. NICS functions today much like it did 20 years ago. When someone wants to buy a firearm, a federally licensed gun dealer contacts the system and usually within minutes federal investigators receive the request and begin searching for clues within three main databases to approve or deny the purchase. The FBI says the system has denied more than 1.3 million firearm transfers since NICS first began operating. If more research needs to be done, the purchase can be delayed for up to three business days. If in that time investigators can't complete the additional background check, federal law allows the gun dealer to proceed with the transaction.

So much for the "instant" part of the program:

In 2015, a white supremacist in Charleston, S.C., was able to obtain a gun after the FBI failed to complete his background check before the three-day deadline. The gun purchase was able to go through and that shooter later killed nine black churchgoers. As NPR reported later, it was discovered the shooter had admitted to possessing a controlled substance during an arrest. That should have denied the purchase on the grounds of "an unlawful drug user or addict."

Of course, there are other instances where a mentally disturbed individual was able to obtain a firearm from family or friends. Such was the case of the Newton school shooter Adam Lanza, who obtained his guns from his mother.

Another loophole is that states are not very good at cooperating with the Feds when it comes to sharing information.

"Like any database, the system is only as good as the records put in that system," says Lawrence Keane of the National Shooting Sports Foundation. "There are some very real world examples of where the background check system was not accurate" Like at Virginia Tech in 2017 when 33 people died, including the gunman. In that case, Virginia court documents released after the rampage showed a judge had previously declared the man "mentally ill" and ordered him to seek treatment. But at the time, Virginia wasn't fully sharing information with NICS. Had that information been in the system, there is a better chance the gunman would not have been able to obtain his guns. Again in 2017, a gunman killed 27 people including himself in Sutherland Springs, Texas. He was an Air Force veteran and purchased an assault-style rifle and two handguns, but a domestic violence conviction during his time of service should have barred him from possessing the weapons. The Air Force never entered that information into NICS.

Expanded background checks are being proposed in this latest round of gun control measures designed to stop mass shootings. Why? If the definition of crazy is to do the same thing over and over and expect different results, then this proposal is nuts. The more impediments the Feds set up to block the legal sale of firearms to law abiding citizens, the more people it seems slip through the cracks and shock us all by massacring people.