"If we can save up about $200 real quick...we can go to the next gun show and find a private dealer and buy ourselves some bad-ass AB-10 machine pistols."
- Columbine killer Eric Harris, who was 17 years old at the time The 1994 Brady Act introduced an essential law enforcement tool to help keep guns out of the hands of criminals:  background checks.

To date, the National Instant Criminal Background Check System (NICS) has prevented nearly 1.8 million criminals and other prohibited purchasers from buying guns. The law also has a deterrent effect—prohibited purchasers are less likely to try to buy guns when they know comprehensive background check requirements are in place.
Unfortunately, current federal law requires criminal background checks only for guns sold through licensed firearm dealers, which account for just 60% of all gun sales in the United States. A loophole in the law allows individuals not “engaged in the business” of selling firearms to sell guns without a license—and without processing any paperwork. That means that two out of every five guns sold in the United States change hands without a background check.
Though commonly referred to as the “Gun Show Loophole,” the “private sales” described above include guns sold at gun shows, through classified newspaper ads, the Internet, and between individuals virtually anywhere.

Unfortunately, only six states (CA, CO, IL, NY, OR, RI) require universal background checks on all firearm sales at gun shows. Three more states (CT, MD, PA) require background checks on all handgun sales made at gun shows. Seven other states (HI, IA, MA, MI, NJ, NC, NE) require purchasers to obtain a permit and undergo a background check before buying a handgun. Florida allows its counties to regulate gun shows by requiring background checks on all firearms purchases at these events. 33 states have taken no action whatsoever to close the Gun Show Loophole.