Americans overwhelmingly support background checks. A 2018 Quinnipiac University poll shows that 97% of Americans support criminal background checks for all gun sales. But under pressure from the gun lobby, Congress and most states have failed to close the deadly loopholes in the background check system.

Federal law only requires licensed gun dealers to conduct background checks. That means that millions of guns are exchanged each year without a check – most often online or at gun shows through unlicensed “private sellers.” People with felony convictions, domestic abusers, the seriously mentally ill, and other people with dangerous histories know about this loophole, and they exploit it every day.

This is exactly how convicted felon Jody Lee Hunt was able to buy the firearm he used to shoot and kill four people on December 1, 2014, in Morgantown, WV. Years before the shooting, he had been convicted of felony kidnapping and sentenced to ten years in prison for abducting a former girlfriend and holding her hostage at gunpoint. As a result of the conviction, he became prohibited from buying and possessing firearms. If he had tried to purchase a firearm at a licensed gun dealer, a background check would have stopped the sale. But West Virginia law does not require background checks for gun sales between individuals who are not licensed gun dealers. So Hunt found a 9mm handgun listed for sale on Facebook and purchased it from a fellow West Virginian who had posted the ad.

Closing this unlicensed sale loophole is a common-sense way to keep guns away from people who are legally prohibited from possessing them. Since 1994, background checks have blocked over 3 million gun sales to felons, domestic abusers, and other people with dangerous histories.

We also need to make sure the background check database is complete. State and federal agencies have failed to send hundreds of thousands of records to the national background check databases. And every missing record is potentially fatal. The Sutherland Springs, TX shooter, who killed 25 people at First Baptist Church, was prohibited from buying guns because of a conviction for domestic violence assault. But he was able to pass a background check and buy multiple guns because the record of his conviction never made it into the system.

As part of a comprehensive gun violence prevention strategy, we must require a criminal background check for every gun sale, and ensure that all relevant records are in the background check system.