• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
PoliticsUnitedHealthcare

The killing of UnitedHealthcare’s CEO highlights a terrifying reality: 3D-printed ‘ghost guns’ are all over

Amanda Gerut
By
Amanda Gerut
Amanda Gerut
News Editor, West Coast
Down Arrow Button Icon
Amanda Gerut
By
Amanda Gerut
Amanda Gerut
News Editor, West Coast
Down Arrow Button Icon
December 12, 2024, 1:04 AM ET
Accused murderer Luigi Mangione allegedly used a 3D printed gun in the fatal shooting of UniitedHealthcare CEO Brian Thompson.
Accused murderer Luigi Mangione allegedly used a 3D printed gun in the fatal shooting of UniitedHealthcare CEO Brian Thompson. Benjamin B. Braun/Pittsburgh Post-Gazette via AP
  • A 3D-printed ghost gun is believed to have been used in the killing of UnitedHealthcare CEO Brian Thompson, just the latest example of violence from the nearly untraceable weapons at the center of national legal debate.

When accused murderer Luigi Mangione, 26, was questioned and searched after being found at a McDonald’s in Altoona, Pa., the contents of his backpack allegedly included hand-written admissions about the killing of UnitedHealthcare CEO Brian Thompson, along with a gun and silencer. 

Recommended Video

Authorities said the black pistol in his backpack had a loaded Glock magazine with six nine-millimeter full metal jacket rounds. Police believe both the gun and the suppressor were 3D-printed. That revelation, coupled with Thompson’s brutal early-morning killing on a New York City street, have set off renewed debate about the ease of obtaining 3D-printed weapons that might ultimately wind up being used to commit crimes. Authorities announced on Wednesday that three shell casings found at the crime scene matched the gun Mangione was found with in Pennsylvania.

A report from the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) revealed that the number of privately made firearms or “ghost guns” recovered by police in criminal cases rose more than 1,000%, from 2017 to 2021, ATF public affairs chief Kristina Mastropasqua told Fortune. During roughly the same period, more than 45,000 suspected ghost guns were reported to the ATF as having been recovered from possible crime scenes, including 692 homicides or attempted homicides, according to the bureau. In 2022 alone, more than 25,000 ghost guns were recovered. The ATF defines ghost guns or privately made firearms (PMFs) as firearms that have been built, assembled, or produced by a person other than a licensed gun manufacturer. 

“PMFs have been on the rise over the past decade,” Mastropasqua told Fortune. 

According to an ATF assessment, ghost guns in the 1980s and 1990s were made from stamped sheet metal that could be bent into shape using tools like hydraulic metal brakes, welding instruments and required technical expertise and experience, to boot. In the early 2000s, tech advances made it easier for people to make ghost guns from commercially available weapons kits. The ATF report revealed that Google and YouTube searches for ghost gun-related terms yielded more than 5 million pages of results and video views ranged between 1.3 and 8 million, depending on the length of time the video had been available. 

Ghost guns gained widespread public attention in 2013, when a California man killed six people on the Santa Monica College campus, including his father and brother. According to the Associated Press, John Zawahri cobbled together an AR-15-style weapon after he failed a background check at a licensed gun dealer. He was killed by police. 

A 2017 shooting involved a Northern California man who killed his wife and four other people after building his own gun. Two years later, a Los Angeles teenager shot and killed two classmates and wounded three more at a school. Just last week, a ghost gun critically wounded two kindergarteners at a small religious school in Northern California, according to law enforcement. 

Generally, it’s legal under federal law to make a gun with a 3D printer, as long as the person isn’t engaged in the business of making or dealing in guns, Mastropasqua wrote in a statement. If they are, they must have a federal firearms license. Before 2022, however, 3D gun-making kits could be sold without background checks or serial numbers, which made it incredibly challenging for police and law enforcement to trace the weapons used in crimes and identify and find shooters, she said. 

“As a result, PMFs are attractive to criminals and others legally prohibited from possessing firearms,” said Mastropasqua. 

In 2022, the ATF updated the regulatory definition of a firearm. The grip frame is the main part of a handgun and, in most designs, it holds the firing mechanism and is where the magazine is inserted. The receiver is the main body of a rifle or shotgun and holds the bolt mechanism. The 2022 ATF rule amendment updated the definition of a firearm frame and receiver to clarify that partially complete parts and kits that can be converted into functional firearms fall under the Gun Control Act. Therefore, companies selling so-called “buy, build, shoot” kits had to be licensed, add serial numbers, and run background checks on buyers. Guns accepted into inventory, including 3D printed weapons, now have to be marked with a serial number. 

However, Mastropasqua noted the rule is limited to the commercial sale of those guns and doesn’t apply to people who make ghost guns for their own use. Plus, the rule is subject to a significant legal challenge and remains an evolving area amid ongoing debate. In October, the Supreme Court heard oral arguments in a case challenging the ATF’s rule, although it remains in effect pending the decision, Mastropasqua said. 

In Thompson’s killing, authorities in Pennsylvania and New York have hit Mangione with weapons charges, in addition to a second-degree murder charge. Surveillance footage shows that Mangione crept up behind the 50-year-old father of two and fired into his back. 

“I have no tolerance, nor should anyone, for one man using an illegal ghost gun to murder someone because he thinks his opinion matters most,” Pennsylvania Gov. Josh Shapiro told the public on Monday.

Join us at the Fortune Workplace Innovation Summit May 19–20, 2026, in Atlanta. The next era of workplace innovation is here—and the old playbook is being rewritten. At this exclusive, high-energy event, the world’s most innovative leaders will convene to explore how AI, humanity, and strategy converge to redefine, again, the future of work. Register now.
About the Author
Amanda Gerut
By Amanda GerutNews Editor, West Coast

Amanda Gerut is the west coast editor at Fortune, overseeing publicly traded businesses, executive compensation, Securities and Exchange Commission regulations, and investigations.

See full bioRight Arrow Button Icon

Latest in Politics

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • Future 50
  • World’s Most Admired Companies
  • See All Rankings
Sections
  • Finance
  • Leadership
  • Success
  • Tech
  • Asia
  • Europe
  • Environment
  • Fortune Crypto
  • Health
  • Retail
  • Lifestyle
  • Politics
  • Newsletters
  • Magazine
  • Features
  • Commentary
  • Mpw
  • CEO Initiative
  • Conferences
  • Personal Finance
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
About Us
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • Pinterest icon

Latest in Politics

trump
Economynational debt
‘The fiscal trajectory is not sustainable’: CBO warns about the highest debt in U.S. history as Trump adds $1.4 trillion to 10-year deficit
By Tristan Bove and Nick LichtenbergFebruary 11, 2026
1 hour ago
walz
PoliticsMinnesota
Tim Walz expects immigration crackdown to end within days with Minnesota in ‘trust but verify mode’
By Steve Karnowski and The Associated PressFebruary 11, 2026
5 hours ago
addiction
LawSocial Media
Google lawyer on YouTube: ‘It’s not social media addiction when it’s not social media and it’s not an addiction’
By Kaitlyn Huamani, Barbara Ortutay and The Associated PressFebruary 11, 2026
5 hours ago
teachers
PoliticsLabor
San Francisco teachers to 50,000 students: no school for you
By Olga R. Rodriguez and The Associated PressFebruary 11, 2026
5 hours ago
Photo of Joe Biden
EconomyInflation
It turns out that Joe Biden really did crush Americans’ dreams for the future. Just look at how the vibe changed 5 years ago
By Jake AngeloFebruary 10, 2026
20 hours ago
lutnick
PoliticsWhite House
Lutnick admits travel to Epstein island, downplays relationship
By Catherine Lucey, Matt Shirley and BloombergFebruary 10, 2026
20 hours ago

Most Popular

placeholder alt text
Economy
America borrowed $43.5 billion a week in the first four months of the fiscal year, with debt interest on track to be over $1 trillion for 2026
By Eleanor PringleFebruary 10, 2026
1 day ago
placeholder alt text
Economy
It turns out that Joe Biden really did crush Americans' dreams for the future. Just look at how the vibe changed 5 years ago
By Jake AngeloFebruary 10, 2026
20 hours ago
placeholder alt text
C-Suite
Meet Jody Allen, the billionaire owner of the Seattle Seahawks, who plans to sell the team and donate the proceeds to charity
By Jake AngeloFebruary 9, 2026
2 days ago
placeholder alt text
AI
As billionaires bail, Mark Zuckerberg doubles down on California with $50 million donation
By Sydney LakeFebruary 9, 2026
2 days ago
placeholder alt text
Economy
China might be beginning to back away from U.S. debt as investors get nervous about overexposure to American assets
By Eleanor PringleFebruary 9, 2026
2 days ago
placeholder alt text
C-Suite
'Don't look at the résumé': Elon Musk admits he's 'fallen prey' to flashy credentials but says conversation matters most when hiring
By Jacqueline MunisFebruary 9, 2026
2 days ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.