Ghost Guns: Hobbyists, Hackers and the Homemade Weapons Revolution
Introduction
A Routine Shooting: Why Should We Care About Homemade Small Arms?
“ . . . attempting to control a technology is difficult, and not rarely impossible, because during its early stages, when it can be controlled, not enough can be known about its harmful social consequences to warrant controlling its development; but by the time these consequences are apparent, control has become costly and slow.”
—David Collingridge (Collingridge 1982)
“Man has created a grandiose world of technology, of which dread and fear are often the result… Fortunately, events in the world and our way of life are not determined by technology alone.”
—Karel Zeman (Muzeum Karla Zemana 2016)
On June 7, 2013, a psychologically disturbed Californian shot his father and brother, and then set fire to the family residence. Emerging from the burning home, he commandeered a passing car. Forcing the driver at gunpoint, he shot at targets of opportunity enroute to his final destination: the Santa Monica College Library. Students and staff scattered. The attacker searched for targets, but he’d picked an inauspicious day for a killing spree: local police were well-staffed for a visit by President Obama. Officers entered the library seconds behind the shooter. After a brief gunfight, 23-year-old John Zawahri lay dead with a warm AR-15 at his feet.
In most respects, the shooting reflected the same macabre banalities that have become familiar. The spree lasted 14 minutes. Nine shot. Six dead. Zawahri fired 70 rounds in the library, but another 1,200 rounds in his magazines spoke to greater ambition. He’d dropped out of Santa Monica College three years earlier, becoming unemployed and withdrawn. Family were concerned about his mental health but didn’t believe him capable of such a rampage. Each detail conformed to a frustratingly common pattern. It was a perfectly routine shooting spree.
Routine except for a few details revealed later. Two years earlier, the Department of Justice had issued a letter denying Zawahri possession of firearms. This generated a disqualifying entry in the Federal Bureau of Investigation’s (FBI’s) National Instant Background Check System (NICS). Zawahri couldn’t pass a background check at retailers and would be arrested if found in possession of guns. Yet, he undertook a wild attack with an AR-15 in a state with some of the country’s strictest gun laws. How did he get his weapon?
When guns are recovered at American crime scenes, detectives usually run queries in the eTrace system maintained by the Bureau of Alcohol, Tobacco, Firearms, and Explosives (BATFE). Functioning similarly (but not identically) to a registry, these records can often trace guns to their retail purchasers. Gun registries and tracing systems are premised on the assumption that all firearms begin as a unit of factory inventory. If we track every firearm produced, we can deduce how some of them end up at crime scenes. Tracing systems are reviewable records of a firearm’s chain-of-custody from its factory origins, through brokers, wholesalers, and retailers, to its ultimate retail buyer. With these records, investigators can solve individual gun crimes, identify trafficking rings, and at least attempt to reduce the flow of firearms from legal supplies to the illicit economy.
These systems bring some benefits, but they have vulnerabilities. Weapons tracing depends on a short string of alphanumeric characters. Licensed gunmakers stamp, engrave, or cast unique serial numbers on firearms at their point of manufacture. These alphanumeric strings are visible on the frame or lower receiver of almost all retail guns in America, and they’ve become the linchpin for firearm tracking.
If Zawahri stole his rifle, detectives could enter its serial number into eTrace, which would return information about the rifle’s legal retailer. Then, detectives could review the retailer’s records and identify whoever originally purchased it. Yet, this rifle had no serial, making it invisible to the tracing system. When a crime gun lacks traceable serials, this often indicates illicit trafficking (Braga et al. 2012). Traffickers use many tactics to acquire and resell weapons without a paper trail. One method is to deface the serials, making guns untraceable even if police recover them. This is illegal. Under the Gun Control Act of 1968 (GCA), defacement is prosecutable. Nevertheless, traffickers deface firearms to obscure evidence of their origins. Nowadays, forensic advancements enable recovery of many defaced serials; however, a thorough effort can obliterate the serial.
If Zawahri’s rifle was defaced, this would leave a scar where the serial was scrubbed away. The gun might be untraceable, but the scar would indicate it was manufactured legally before being stolen or trafficked. Yet, this rifle had no scar; its smooth metal receiver spoke no tales. Zawahri wasn’t incorrectly cleared by America’s much-criticized background check system, and he hadn’t stolen the gun. Instead, he had cobbled together a semiautomatic rifle using a hodgepodge of legally acquired parts. John Zawahri built himself a “ghost gun.” Until the day of the shooting he was the only person that knew it existed.
Zawahri bought the rifle’s lower receiver as a partially finished blank. Under federal law, blanks don’t qualify as “firearms” until a sufficient proportion of work necessary to make it functional is completed. Before completion, blanks are legally indistinct from any object in the vague shape of a gun part. Blanks aren’t serialized, require no background checks, and can be legally possessed by people who are prohibited from owning functional guns. Secondary components like slides, barrels, and fire controls also don’t qualify as firearms. Every component of Zawahri’s weapon could be purchased without a background check and completed at home. Detectives discovered Zawahri’s workspace filled with inexpensive tools, unfinished parts, and a few more homemade guns.
Cases like these have fueled speculation about the security impacts of homemade, or do-it-yourself (DIY) weapons. Independent gunmaking may seem like a futuristic concept. In reality, guns have been made independently for a thousand years. Home gunmaking was a backwater for security research until the precipitous rise in media coverage following the first 3D-printed firearms. Before the 2010s, researchers often characterized homemade guns as a curiosity of the developing world, generally dismissing them as cheap, crude, and irrelevant substitutes for the real thing.
Today, there is growing concern that criminals and extremists are embracing homemade guns. Meanwhile, DIY firearms, accessories, and modifications have become popular among legitimate consumers in America. Research on homemade weapons has always been overshadowed by research on conventional firearms. This is justified. The sheer number of conventional firearms (and the magnitude of their social interactions) has always outstripped the criminal impact of homemade guns in the developed world. Consequently, we know comparatively little about the current status or future implications of DIY guns. Available information is a mash-up of nonstandardized sources: police reports, studies of craft weapons in developing countries, tabloid coverage, serious journalism vacillating between technical admiration and concern for public safety, sweeping generalizations by lobbyists and legislators, tutorials, reviews, and analyses by firearms journalists and small arms researchers, and expressions of schadenfreude by DIY provocateurs.
Because DIY gunmaking has only recently become a topic for mainstream research, many police agencies have not kept reliable records of homemade firearms they encounter. Some agencies have recently improved data collection, but many sources are incomplete, nonstandardized, inaccessible to the public, or cover a short period of time. The longstanding characterization of DIY firearms as a marginal counterpart to “real” guns has limited efforts to understand their implications. Regulatory proposals add up, but many are based on incomplete information.
What Is a Ghost Gun?
Independently fabricated small arms go by many names: “homemade,” “DIY,” “expedient,” “improvised,” “craft,” “crypto,” “80%,” “component” builds, “knockoffs,” “counterfeits,” “zip” guns, and a variety of slang around the world. Yet, each of these terms is clearer than the one embraced by media: ghost guns.
Homemade firearms have existed for a millennium, but the term ghost gun has more recent origins. The first media use of the term to reference actual firearms might be a 2001 article on plastic flare guns that the Real Irish Republican Army converted to fire live cartridges (Insall 2001). More recently, the term became popular after California senator Kevin de León held a press conference in 2014 where he displayed a homemade ghost gun, and promoted new regulations. De Leon’s photo-op was well-timed: it followed a spate of coverage on 3D-printed guns. Printable guns were promoted the two years prior by Cody Wilson, a Texas law student, flamboyant crypto-anarchist, and founder of the digital gunmaking firm Defense Distributed.
Articulate yet bombastically provocative, Wilson relished the overblown fear of his single-shot 3D-printed Liberator handgun, which he described as his printed ghost gun as early as April 2013 (Camiel 2013). In the following years, Wilson undertook a promotional blitz, explaining to a pearl-clutching media how printable firearms portended the end of gun control. Google Trends reveals spikes in searches involving the terms ghost gun, homemade gun, and 3D-printed gun between 2013 and 2020, coinciding with media reporting on Defense Distributed, its products, and legal battles. Defense Distributed and many independent gunhackers have improved the engineering of digital firearms since.
Meanwhile, frame builds or 80% firearms had quietly popularized for years. These are conventional firearms built from unfinished components. Many retailers and hobbyists rejected the ghost gun term as a sinister rebranding of a longstanding practice with little historic connection to crime. Other retailers embraced the hype as a marketing ploy. To the detriment of this book’s promotion, the best URLs containing the term ghost gun are owned by build kit retailers. Mainstream journalists were unsettled by the untraceability of ghost guns, but this same quality played a role in their popularization. When commentators decried untraceable guns that users could build without registration or background checks, many Americans clicked purchase. In a wider sense, the popularization of the ghost gun term has laid bare its role as a promotional gimmick and rallying cry for advocates on both sides of America’s toxic gun debate.
Context matters. If the primary concern about ghost guns is that they will not appear on registries, it may surprise some readers to know that ghost guns are most guns. Small Arms Survey estimates there are 857 million civilian-held firearms in global circulation and 88 percent of that total is unregistered (Karp 2018, 3). Perhaps a more relevant definition is that a ghost gun has no traceable serial numbers. Serialization may seem like a longstanding regulation, but it wasn’t universally applied by American manufacturers until the 1968 GCA. Guns made before 1968, guns whose manufacturing or sales records are lost, defaced guns, and many foreign-made guns, may be untraceable (U.S. Department of Justice BATFE 2011, 3).
Lack of traceability fuels concern about homemade guns. Yet, most of the world’s guns are unregistered, and many can’t be traced through serials. Even with serial numbers, most crime guns are stolen or trafficked, ensuring that registries and tracing systems will finger the weapon’s legal purchaser rather than its subsequent illegal user. In America alone, 250,000–500,000 guns are stolen annually, with 80 percent unrecovered after six months (U.S. Bureau of Justice Statistics 2012). The New York Times repeats a common estimate that approximately 50,000 guns are trafficked across state lines annually (Aisch and Keller 2015). These figures may underestimate the true scale of trafficking, yet they indicate an illicit supply many times larger than needed to generate all gun homicides per year.
Registries and serial numbers help police identify trafficked and stolen crime guns and monitor trends in theft and trafficking. However, numerous surveys indicate that most offenders don’t purchase or possess their guns legally. Gun rights advocates question the role of firearm tracking infrastructures in deterring gun crimes, as most offenses are committed by people who aren’t identified in the gun’s paper trail. Stolen guns, trafficked guns, defaced guns, and unregistered homemade guns are all invisible to tracking systems until recovered by police. In America, it’s fairly easy to acquire guns in ways that separate them from their legal chains-of-custody. In that regard, homemade guns only complicate an existing problem.
A security-relevant definition of ghost guns might also include the vastly larger number of commercial firearms that are unregistered, untraceable, or circulating illicitly. It’s not absurd to characterize most of the world’s illicit guns as ghost guns insofar as no recordkeeping system will provide police with the gun’s current whereabouts or the name of its illegal possessor. Nevertheless, when most people talk about ghost guns, they are clearly talking about homemade guns rather than many millions of conventional firearms that are nearly as difficult to track. Conversely, not all homemade guns are ghost guns. Some jurisdictions provide a regime for
DIYers to serialize and register homemade firearms. These frameworks are controversial in America, but do represent an approach to reducing the ghostly character of homemade guns (provided sufficient public cooperation can be achieved). However, reaching the political agreement and public cooperation needed to make these laws effective, would require a strengthening of sociopolitical trust that has become elusive in American discourse.
Since many readers assume that homemade guns are synonymous with ghost guns, this book primarily focuses on the implications of homemade firearms as they interact with legacy regulatory regimes. Diversity of style, fabrication method, capability, and appeal are all factors for policy. Yet, the most basic definition of DIY products is that they’re manufactured independently of licensed commerce. Conventional trafficking begins with theft and diversion: skimming commercial guns from legal supplies. DIY firearms involve fewer interactions with the commercial regulatory systems that have underpinned gun control for decades.
While vastly overshadowed by conventional products, DIY guns are catching on. Much DIY gunmaking has been legal under American law, and the vast majority of America’s DIY gunmakers have no connection to crime. Yet crime is inevitable. In 2014, bank robbers used a homemade rifle in California. The following year, a Stanford student made a gun for a murder-suicide. Several active shootings have involved DIY products or modifications. Police periodically disrupt illegal gunmaking operations. Some cases are odd. In 2017, a Maryland Honors student built a Glock and regularly brought it to high school, claiming fear of active shooters. In 2018, a Broadway puppeteer was caught printing a handgun at work. Weapons traces for DIY products have increased in the United States, but homemade weapons still appear to be responsible for a small proportion of America’s overall gun crime. Much consternation emanates from jurisdictions with stricter laws. A new source of firearms may prove most disruptive in jurisdictions where illicit guns are harder to get.
Media coverage of the modern gunmaking phenomenon has occasionally approached hysteria, but some concerns have merit. Around the world, independent makers are improving their products. Even in countries with strict controls, DIY has become a source of illegal weapons largely untouched by legacy regulation. The traditional view of homemade weapons would place them in corrupt, economically disadvantaged, and conflict-ridden locales. This image still rings true. Homemade guns have been prevalent in developing nations. Since the earliest days of colonialism, local artisans reverse engineered trade guns. Much of today’s illegal gunmaking (and violence) still reflects an economic and social welfare differential between global north and south.
DIY gunmakers have gained attention for their adoption of digital fabrication and nontraditional materials. Digital fabrication converts objects into cyber-physical goods existing on an uneasy continuum between information and physical thing. While digital manufacturing drives incredibly beneficial innovations and is increasingly integrated with mainstream industry, digitization of homemade guns struck some gun control advocates as an outrageous development. Meanwhile, DIY provocateurs cheer digital fabrication’s seeming guarantee of firearm access irrespective of law. In that regard, DIY guns are among the early regulatory challenges brought to us by the emerging 4th Industrial and Open Source Revolutions.
DIY guns reflect a growing divide between industrial regulatory systems and the realities of an increasingly postindustrial world. Not only an emerging issue for politics and policing, they foreshadow a contest between the unknown necessities of twenty-first-century security and traditional safeguards for privacy, speech, and communication. Manufacturing capability has diffused since industrialization. More things can be made, and more people can make them. Digitization increasingly liberates manufacturing from traditional geographic, legal, and logistical constraints. We are only starting to grasp the implications, but postindustrialization is expected to transform society.
Gunmakers inevitably counted themselves among the early adopters. By modern manufacturing standards, guns are simple machines. Guns were invented centuries before industrialization, but the artisanal model had its drawbacks: productivity plateaued at the limits of labor efficiency, and precision plateaued at the limits of human performance. Eventually, governments wanted more and better guns than artisanry could provide. Modern factory techniques were incorporated into gunmaking before they were applied to most consumer goods. Yet, while guns were a catalyst of industrialization, industrial techniques have never been required to make them.
The principles behind firearms have been unchanged since the “fire lance” of tenth-century China. The fire lance was a tube attached to a pole. It launched projectiles similarly to a shotgun. There have been many innovations since, but despite sleek designs and precise manufacturing tolerances, most of today’s firearms are mechanically similar to guns invented more than a century ago. The underlying concepts were conceived by innovative artisans who predated modern chemistry, physics, and factory methods by several centuries. What differs today is the accessibility of tools and information. The Digital Revolution, 4th Industrial Revolution, and Open Source Revolution are combining to facilitate independent design, manufacturing, and modification of firearms among many other products. American hobbyists and international gunhacking subcultures have driven innovation in homemade guns. Criminals and extremists are making them illicitly. The role of DIY is significant in some countries, yet the challenges it poses are only beginning to be understood. This book explores the security implications of DIY
weapons, the practical aspects of making them, and the wider technological, legal, and civil liberties implications of recalibrating traditional gun controls to address modern DIY.
The Open Source Revolution’s challenges will not be limited to guns. Chapters 1–2 describe a spectrum of manufacturing advancements that are applicable to home gunmaking. DIY gunmaking is often perceived as an emerging technology issue. Technology certainly plays a role. However, artisanal production was the norm until the nineteenth century. Historically, weapons regulation has reflected assumptions about how they’re made.
Reliable data on DIY weapons is limited, but it’s evident that they’ve improved and proliferated. What are the tricks of the illegal gunmaker’s trade, and how do they challenge legacy regulation? Why would criminals or terrorists substitute DIY guns for conventional products? Chapters 3–5 explore these and other security implications.
How does DIY gunmaking interact with legacy law and political culture? Chapter 6 explores the sociopolitical dynamics of DIY gunmaking in the United States and provides limited comparisons to the experience of Australia: a nation superficially similar but vastly different on gun policy, culture, and outcomes. How might traffickers exploit each country’s criminal incentives and regulatory vulnerabilities? The answers underscore the complexity of crime control in a postindustrial world.
Gunmaking is facilitated by a vast material-informational ecosystem. Much firearms information is open source and has traditionally been uncensored. As DIYers leverage information technology, proposals to combat them have reflected an expanding scope of surveillance and censorship. Some proposals are expansive enough to make bedfellows of gun rights, free speech, open source, and privacy advocates. What are the implications of controlling homemade weapons through controls on information and commerce? Chapters 7–8 explore that question—asserting that that the regulatory regimes necessary to stop homemade weapons may prove as socially transformative as the weapons themselves.
The world will be different if illegal gunmaking proliferates. It will also be different if we introduce expansive controls, and more different still if we implement expansive controls that don’t work. How can liberal society adjust as technology makes it easier to produce weapons and contraband? We have options, but they require an honest assessment of risks and harms, and reconsideration of the binary logic that dominates gun politics. Chapter 9 lays out strategies to balance the legitimate values at stake.
More sociopolitical deconstruction than empirical criminology, this book examines the interactions of gunmaking technology, politics, and policy. This is a challenging task, and no book can fully do this issue justice. The underlying technologies and political developments have advanced too rapidly to pronounce their results in print. Further, weapons trafficking is a poorly tracked criminal subsector. How we describe gun trafficking, and the legal regimes best suited to minimize it, can vary considerably. Drawing policy-relevant connections is hard enough that some scholars have suggested evidentiary requirements for gun policy be lowered below the normative standards of social science. Referring to these difficulties, researchers Philip Cook and Jens Ludwig (2006) argued, “For many social policy applications we either must give up on the goal of evidence-based policy, or develop a broader conception of what counts as evidence” (694).
Analysis of weapons policy is always subjective to some degree. As Wright et al. (1983) observed decades ago, “Virtually all of the literature on these topics is polemical to some extent. . .” and any conclusion “does not depend at all on the numbers themselves, but on the implications one is willing to draw from them” (3–4). Political polarization ensures that even fair-minded research will be accused of bias.i This book derives from a range of sources that don’t easily conform to the architecture of a standardized study. The book addresses security implications, but largely sidesteps suicide. In America, suicide is the most common form of firearm mortality. However, despite its greater toll, political psychology renders self-harm a less pressing issue for security or politics than criminal violence, a reality briefly addressed in chapter 6.
Guns are among the most politically coded issues in contemporary America. Battle lines are forming on DIY guns before we fully understand them. Criminologist and retired BATFE Program Manager William Vizzard described how factions are already forming: “You’ve got the libertarian side which coalesces with the gun rights folks, and the regulation proponents who coalesce with the ‘I don’t like guns’ folks” (Interview 2016). An Australian criminologist lamented, “People go with their prejudices. What do you do when science is politicized?” (Interview 2016).
America’s gun debate is nothing short of toxic. Several respondents cautioned that guns are a third rail in American politics. In a discourse characterized by shaming and misinformation, some respondents required confidentiality. One respondent from a gun control advocacy group warned that I might be threatened by “pro-gun extremists.” During doctoral research on this topic, some faculty at a gunsmithing school agreed to participate in interviews. However, administrators nixed it because my university-mandated interview consent paperwork referred to firearms as “weapons.” A few stakeholders from the firearm industry rebuffed invitations, assuming that I’m a “liberal antigun researcher,” though others didn’t jump to this conclusion after sufficient conversation.
Conversely, security studies professor and conventional weapons researcher Brett Steele cautioned: “You’re actually doing something profoundly taboo in social science: you’re trying to write in an objective manner about guns. When you try to sell this to mainstream academia, they’ll dismiss you as a gun nut unless you have a critical bent” (Interview 2016). This warning might sound frivolous, but some research suggests university faculties harbor biases against applicants with perceived connections to gun rights advocacy (Yancey 2017, 57–69). The culture war over guns generates extensive media coverage, yet the tenor of that coverage may further fuel the conflict. Many gun rights supporters are distrustful of journalists and academics, assuming these liberal-dominated fields will never offer a positive depiction of gun culture. This perception plausibly contributes to declining trust in mainstream media and the rise of alt-media and populist politics. In 2018, Gallup found that 75 percent of U.S. independents, 66 percent of moderates, and 95 percent of conservatives reported their trust in mainstream media had declined in the last decade. One study suggests that relentlessly negative coverage toward gun rights advocacy may strengthen the National Rifle Association (NRA) and conservative media (Patrick 2013).
DIY gunmaking is increasingly relevant. Yet, it’s impossible to understand its implications without relating homemade guns to the vastly larger role of commercial firearms, and the toxic politics and oft-disputed policies meant to regulate them. To hack through this jungle, I reviewed thousands of relevant documents, and interviewed (and in a few cases received written feedback from) 85 subject matter experts.ii I spoke with current and retired law enforcement, security, counterterrorism, and cybersecurity specialists, legal scholars, political scientists, criminologists, prosecutors, elected officials, security screeners, industrial designers, makers, hackers, journalists, and advocates on both sides of the mandatory binary we call gun politics.
Gun policies and the research around them can be quantitatively incomplete, analytically subjective, politically contentious, economically impactful, emotionally laden, practically
important, and politically charged. Whether modern DIY breaks or reinforces our preconceptions, the first step toward addressing an emerging challenge is to understand why it’s a challenge at all. Technology contributes to modern DIY, and technologic anxieties drive much concern about homemade guns. It’s impossible to understand DIY gunmaking without understanding the technology behind it. Ready or not, the Open Source Revolution is here.
With thorough analysis and balanced reporting, GHOST GUNS: Hobbyists, Hackers, and the Homemade Weapons Revolution is an essential resource for readers seeking to understand the rise of homemade firearms and future options for managing it.
For more than a century, strict gun control was possible because firearms were produced in centralized industrial factories. Today, the Fourth Industrial Revolution, combining old and new technologies, threatens to upend this arrangement. An increasing number of hobbyists, “makers,” technology provocateurs, and sophisticated criminals are proving that you don’t need a factory to make guns anymore.
The security challenges of this transformation are increasingly apparent, but the technologies behind it hold tremendous potential, and so while to ignore the security implications would entail risks, the costs of new policies also must be evaluated. “Do-It-Yourself,” or DIY, weapons will bring significant ramifications for First and Second Amendment law, international and homeland security, crime control, technology, privacy, innovation, and the character of open source culture itself. How can liberal society adjust to technologies that make it easier to produce weapons and contraband?
Informative and thought-provoking, GHOST GUNS carefully analyzes the technical, legal, social, political, and criminological trends behind this challenging new area of illicit weapons activity:
• Provides readers with informative background on DIY gun laws and legislative trends, and fascinating descriptions of legal and illegal practices with homemade weapons around the world
• Presents in-depth explanations of the consumer appeal, technology, economics, politics, and enforcement challenges behind America’s quickly growing DIY gun-making phenomenon
• Evaluates the current and future appeal of homemade weapons for differing types of crime and terrorism
• Offers a series of forward-looking recommendations for weapons control and security policy in an increasingly “post-industrial” 21st century
Mark A. Tallman, PhD, is an Adjunct Professor at Colorado State University-Pueblo’s Center for the Study of Homeland Security and Center for Cyber Security Education and Research. He is a Senior Security Consultant and Executive Director of Creative Assurance, a Colorado-based security and emergency planning consultancy. He contributes to the law enforcement blog Calibre Press, and edits MakingCrimes.com.