The murder of UnitedHealthcare CEO Brian Thompson in Manhattan has spotlighted the fury that many Americans feel toward the nation’s dysfunctional health insurance system.

It has also tapped a profane undercurrent in national discourse today that makes otherwise rational people think it’s acceptable to express such fury with dehumanizing jokes and memes about the violent taking of a life.

What isn’t getting enough attention, but should, is the alleged instrument of that violence.

Murder suspect Luigi Mangione was arrested in Pennsylvania carrying a “ghost gun” that authorities believe was the murder weapon. It’s part of a burgeoning industry of untraceable weapons that Congress should have cracked down on years ago.

Firearms manufacturers are required to stamp each new gun with a serial number. Acquisition and transfer records are required when the weapon is sold and resold. Criminal background checks are required for any gun purchase made through a federally licensed dealer. All of it is designed to both prevent gun violence and to aid police in tracking down perpetrators of violence when it happens.

“Ghost guns” are guns assembled by buyers from mail-order kits and/or 3D-printer plans instead of being sold as fully functioning weapons. The only logical reason for this roundabout process is to make it easier for people who aren’t supposed to have weapons to get them — and to make it harder for police to trace them when they’re used in crimes.

Common sense dictates that, regardless of how a gun came into being, federal requirements regarding serial numbers and the rest should still apply. A gun assembled at home can be used to kill with just as much finality as one bought in a gun shop.

Yet the legal status of ghost guns today remains in limbo.

Congress has refused to specify in federal law that ghost guns must come under the same restrictions as other guns. The Biden administration responded with administrative rules that require manufacturers of ghost gun components to adhere to the same regulations as firearms manufacturers, including stamping the parts with serial numbers and keeping relevant sales records.

Opponents sued to overturn those restrictions, arguing that gun kits aren’t guns — never mind that they can be assembled by buyers into functioning weapons in as little as 30 minutes. The U.S. Supreme Court heard arguments in the case (Garland v. VanDerStok) in October; its opinion is pending.

The number of ghost guns recovered at crime scenes has exploded 10-fold in just the past five years, from under 1,800 in 2016 to more than 19,000 in 2021, according to data from the Bureau of Alcohol, Tobacco, Firearms and Explosives.

While the alleged assassin could just as easily have killed Thompson with a standard-issue handgun, the fact that it was apparently a ghost gun could conceivably complicate the case against Mangione.

Police say the ghost gun found on Mangione is “consistent” with the type of gun used in the killing. But that doesn’t provide the solid link they might be able to establish if they could work with a serial number, manufacturing records, background checks and other law enforcement tools that, by intentional design, are not available for ghost guns.

By failing to pass commonsense legislation stamping ghost-gun restrictions into federal law, Congress aids the criminals who are aided by this niche of the firearms industry.

St. Louis Post-Dispatch Editorial Board/Tribune News Service

Editorial cartoon by Chip Bok (Creators Syndicate)