How a CEO's murder offers a dark glimpse into the anonymous world of 3D-printed guns

A man in his thirties known online only by his screen-name instantly recognized the gun seized from the suspect in the killing of the UnitedHealth CEO earlier this month.

As a photo circulated online the fake New Jersey driver’s license and 3D-printed gun police found on Luigi Mangione, he spotted the tell-tale stippling pattern on the firearm’s grip.

“It’s mine lol,” the man, known as “Chairmanwon” quipped on X Dec. 9. Then he quickly deleted the post.

Mangione has been charged in the murder of Brian Thompson. The high-profile case has thrust not only "ghost guns," which have no identifying serial number, into the national debate, but underscored the burgeoning 3D-printed variety. With those, DIY-gunmakers download a design file, and feed it into a machine that prints layers of plastic to make some components of a gun.

Someone has to create and refine those design files to make the resulting guns function better and fit comfortably in a shooter’s hand.

That’s where Chairmanwon fits in.

He spoke with USA TODAY under the agreement he would not be named for fear that fanning the online mob tied to the shooting could endanger his safety.

He’s not entirely anonymous: He’s appeared several times on YouTube streams in his black-framed glasses and red beard. He’s also posted publicly that he’s in his 30s, has moved around the United States seeking more friendly gun laws, and has a background in furniture design.

When he saw Mangione’s gun, he said, his first reaction was surprise.

“I was shocked that it was 3D printed, and surprised it was such an old file, it was from 2021,” the man said. “It’s America, and this isn’t the easiest way to acquire a functioning firearm.”

He said his design is called the FMDA 19.2 CMW Stipple. That’s a variant on the Glock FMDA 19.2 model, released by the same open-source collective where he uploads his designs, Deterrence Dispensed.

DetDisp as it’s known, also hosted the FGC-9, a gun design traced to crime and terrorists around the globe. The New York Times identified DetDisp’s figurehead, an outspoken designer known as Ivan the Troll, as a 26-year-old Illinois-man earlier this year.

Chairmanwon described himself as a firearm enthusiast who enjoys the firing range and as a pro-gun Democrat. He said he hasn’t been contacted by any investigative authorities and doesn’t worry about civil liability, since he’s far removed from how the guns he designs are eventually used.

“There’d be nothing I could do to help. I don’t host files myself,” he said, adding that he distributes them for free. “I can’t imagine what a lawsuit would look like, I can’t see how this is any different than suing Glock.”

Glock, the Austrian gun-making behemoth, has indeed been sued over its designs, most recently by the City of Chicago, and the states of New Jersey and Minnesota. In general, a 2005 federal law shields gun manufacturers and dealers from liability from crimes committed with their products.

“There are people who break state and federal law. But my fundamentals are: Hey, ‘I’m going to make my own firearm and use it, which is legal and protected,’” Chairmanwon told USA TODAY.

Landscape of ghost gun laws emerges

No federal laws ban 3D-printed or privately made firearms.

But as police agencies have increasingly recovered untraceable homemade guns at crime scenes, some state legislatures have passed stricter rules. The state where Chairmanwon lives does not have these restrictions.

If authorities can prove Mangione downloaded and printed his firearm in Pennsylvania or New York, he could face additional gun charges.

Fifteen states now require serial numbers on homemade parts or ban 3D printing them. Some even ban the distribution of 3D printing instructions.

President Biden and the Bureau of Alcohol, Tobacco, Firearms and Explosives added regulations in 2022 that say the ghost gun parts kits themselves qualify as “firearms” that should be regulated by the Gun Control Act.

Gunmakers challenged those rules at the Supreme Court. In October, the court heard oral arguments, but justices signaled they were leaning toward upholding the rules.

Civil liability for ghost guns still being tested in court

Among those attorneys pushing for more accountability for the Wild West of homemade gun designs is New York-based firm Bloch & White.

They’re suing JSD Supply, an online ghost gun retailer in Michigan. That site sold a ghost gun parts kit to 17-year-old Kyle Thueme, who accidentally shot his 17-year-old friend in the eye.

“The challenge with 3D printing is you take the distributor out, the manufacturer is the end user,” attorney Benjamin White said.

The First and Second Amendment protect much of the private creation of firearms and online instructions, White said. And he compared the debate to that of whether social media platforms can be held responsible for policing content on their sites.

“Once you start holding platforms responsible, those platforms get nervous that liability is around every corner,” White said.

Chairmanwon said much of the 3D-printing community is dedicated to Libertarian, freedom of speech and anti-copyright causes. He considers himself a minor contributor to a larger collective of designers that mostly stay within the bounds of the law themselves. What users do with their plans is not their concern.

Regulating instructions or manuals for dangerous weapons or bombs has some historical precedent.

Federal law prohibits “teaching, demonstrating or distributing information on how to make or use explosives, destructive devices or weapons of mass destruction,” if it is intended to commit violence.

Those laws came in the wake of the 1995 Oklahoma City bombing and fear others could download “cookbooks” for bombs. They were backed at the time by Senators Dianne Feinstein and Joe Biden.

A Department of Justice analysis in 1997 during the debate concluded: “The First Amendment would impose substantial constraints on any attempt to proscribe indiscriminately the dissemination of bombmaking information. The government generally may not, except in rare circumstances, punish persons either for advocating lawless action or for disseminating truthful information – including information that would be dangerous if used – that such persons have obtained lawfully.”

Anonymity may be coming to an end

“For obvious reasons, I’m trying to keep this situation at arms-length,” Chairmanwon told USA TODAY, referencing the use of a gun he designed in the murder of Thompson. Mangione has now drawn 11 charges, including first-degree murder and “an act of terrorism.”

“I have much less to do with this design in question than has been talked about on Twitter,” he said, referencing his grip design that added to an existing plan.

Such distancing is troubling to gun control groups that believe manufacturers, designers and users all share accountability for gun violence.

“3D-printed firearms undermine all of our gun safety laws — they’re a dream come true for criminals who want to avoid detection and a nightmare for law enforcement,” said Nick Suplina, senior vice president of law and policy at Everytown for Gun Safety.

“The online spaces where these designs are distributed are saturated with toxicity, extremism, and a callous disregard for the death and suffering caused by these guns. It’s no surprise these people prefer to hide behind a username — this allows them to shirk responsibility for the damage they’ve done.”

Nick Penzenstadler is a reporter on the USA TODAY investigations team. Contact him at [email protected] or @npenzenstadler, or on Signal at (720) 507-5273.

This article originally appeared on USA TODAY: How Mangione's gun offers a dark glimpse into world of 3D gun design