Ghost Guns, Real Violence

This session analyzed how additive manufacturing and digital weapons blueprints are reshaping extremist violence. It addressed regulatory blind spots, online distribution networks, and implications for U.S. enforcement policy. This session featured Dr. Yannick Veilleux-Lepage, Associate Professor, Department of Political Science and Economics, Royal Military College of Canada and was moderated by Dr. Omar Mohammed, Senior Research Fellow at the Program on Extremism.

On April 16, 2026, the Program on Extremism at The George Washington University held the first of nine monthly sessions tied to the inaugural issue of its new Global Extremism Papers journal, which focuses on the intersection of extremism, emerging technology, and national security. This session, titled "Ghost Guns and the Real Violence," featured Dr. Yannick Veilleux-Lepage, Associate Professor of Political Science and Economics at the Royal Military College of Canada and one of the foremost experts on extremist innovation and the proliferation of 3D-printed firearms. The event was moderated by Dr. Omar Mohammed, a Senior Researcher Fellow at the Program on Extremism.

Dr. Veilleux-Lepage's paper builds on his earlier 2024 article "Printing Terror," published in the CTC Sentinel, which surveyed 35 cases of racially and ethnically motivated violent extremist (RMVE) actors acquiring or manufacturing 3D-printed firearms and focused primarily on their motivations. For this new paper, he returned to the dataset, which has since grown to more than 52 verified cases compiled from court records, law enforcement collaboration, and media coverage. Applying a stricter two-part threshold, requiring both a clear move from ideation to planning and an active effort to obtain the material needed to make a plot feasible, he narrowed the dataset to 30 cases with genuine operational intent. These plots spanned the United Kingdom, United States, Germany, Australia, Italy, the Netherlands, Croatia, Finland, Iceland, Ireland, Portugal, and Singapore, underscoring that this is a global phenomenon rather than one confined to a single region. He cautioned throughout that these numbers likely represent only a fraction of actual cases, given the secrecy inherent to terrorist plotting, the tendency of ideological motives to surface only later in investigations, and defendants' incentives to downplay ideological intent after arrest.

Turning to who these plotters are, Dr. Veilleux-Lepage explained that the 30 plots involved 55 individuals, ranging in age from 16 to 66 and overwhelmingly male (93 percent). He noted with interest that two of the three female plotters in the dataset appeared to have entered their plots through intimate partner relationships with male co-plotters, a pathway he suggested merits further study. Ideologically, the plots reflected the broader far-right landscape, including neo-Nazi, accelerationist, white supremacist, and anti-government currents, with plotters frequently citing prior mass-casualty attackers such as Anders Breivik, Brenton Tarrant, and Dylann Roof as inspiration. He noted the particular and somewhat unexpected prominence of Stephan Balliet, perpetrator of the 2019 Halle synagogue attack, as a touchstone for these plotters despite his attack's comparatively low fatality count, suggesting Balliet's significance may be specific to the 3D-printed-firearm subculture.

Only two of the 30 plots progressed to actual violence: the 2019 Halle attack, in which Balliet was unable to breach the synagogue door and instead killed two bystanders nearby, and a 2023 case in Finland in which a cell livestreamed weapons testing on an online platform before planting an IED at, and later firing on, the home of a Black family. Across the dataset, targets closely tracked familiar RMVE priorities: racialized and religious minorities, political institutions, law enforcement, and infrastructure, with one German cell notably discussing attacks on rival extremist actors. The role that 3D-printed firearms played in each plot varied considerably. In nearly 40 percent of cases they served as the primary weapon system, in 13 percent they were used to modify conventional firearms (for instance, through 3D-printed auto sears), and in roughly half the firearms remained in development. Dr. Veilleux-Lepage illustrated this variation through contrasting cases: one plotter told an undercover agent he would prefer a conventional firearm but would settle for a 3D-printed one if necessary, while a soldier arrested with legally obtainable access to conventional firearms chose to build 3D-printed weapons instead, largely for ideological reasons. He identified four broad motivations driving this choice: ideological or symbolic value, including the ability to manufacture a weapon outside state control; the capacity to complement and increase the lethality of existing firearms; substitution when conventional firearms are unavailable; and financial incentive, since components like auto sears can be produced cheaply and sold at a substantial markup.

Among the most striking findings was that 70 percent of the plots also involved some degree of engagement with improvised explosive devices, whether through manuals, precursor materials, or constructed devices. Dr. Veilleux-Lepage argued this has significant implications for officer safety during searches and for how investigations are scoped, noting that many of these plots were first uncovered incidentally during routine firearms-trafficking investigations rather than national security probes, in part because firearms investigators are not always trained to recognize ideological indicators. He recommended that search warrants in suspected 3D-printed firearm cases explicitly authorize the seizure of ideological material for this reason. He also discussed the evolving policy landscape, including recent Canadian legislation explicitly addressing 3D-printed firearms and Australian state-level laws, while noting that regulatory approaches vary significantly by jurisdiction and that efforts in the United States face distinct First and Second Amendment considerations.

During the discussion that followed, Dr. Veilleux-Lepage addressed audience questions on the manufacturing of homemade ammunition as a further way plotters are working around traditional bottlenecks; on the range of end users beyond RMVE actors, including violent dissident Republican groups and jihadist-linked cases; and on how cases like the killings of Shinzo Abe and Brian Thompson relate to, but differ from, the specifically 3D-printed firearm phenomenon he studies. Responding to a question from Public Safety Canada about the country's upcoming firearms classification review, he pointed to Canada's approach of criminalizing intent alongside possession of files as a promising model, while noting that the precise legal threshold for "intent" will likely need to be tested in court. He closed by emphasizing that the field remains better equipped to study the forensic and technical dimensions of 3D-printed firearms than the broader online ecosystem, of files, communities, and platforms, that sustains them, an area he said only a handful of researchers are currently examining.