The Assassination of Shinzo Abe and the Threat Posed by DIY Weapons

An individual shot and killed former Japanese Prime Minister Shinzo Abe with an improvised firearm on July 8 while Abe was delivering a campaign speech in the city of Nara. The suspected assailant, identified as 41-year-old Tetsuya Yamagami, fired two shots from a device that resembled a sawed-off shotgun, later telling police that he had made his own firearms by taping steel pipes together with parts purchased online. Investigators recovered several other homemade or do-it-yourself (DIY) weapons from Yamagami’s home following the attack. 

In a country where gun violence is exceedingly rare, the killing came as a complete shock. The process for legally obtaining a firearm in Japan is so onerous that few choose to pursue it. Moreover, the penalties for illegal possession or use of a firearm are so stringent that even Japan’s organized crime syndicates, the Yakuza, limit their use against civilians. 

The weapon used in the Abe attack was rather crude. But it signals a significant change in the nature of violent attacks: The proliferation of emerging personal technologies like drones, 3-D-printed weapons, and other innovations will likely open the door for more attacks against high-profile figures in the future. 

These technologies have already endangered other political leaders. In August 2018, two drones packed with explosives were used in an unsuccessful assassination attempt targeting Venezuelan leader Nicolas Maduro. In November 2021, Iraqi Prime Minister Mustafa al-Kadhimi was nearly assassinated after an explosive-laden drone struck his residence and exploded. Even where the weapons lack sophistication—as appears to be the case in the Abe attack—terrorists and violent non-state actors will continue to look for loopholes and workarounds to circumvent current security measures. This does not preclude a shift away from tech and toward “dumb” weapons, including improvised firearms or vehicle attacks, a trend popularized by the Islamic State several years ago. 

Improvised firearms may not be a new threat, but they are becoming increasingly easy to produce. Indeed, the barriers to entry are remarkably low: Anybody with the time and minimal resources required to tinker with the construction of firearms can learn to fashion a DIY deadly weapon in various online communities. This means that in the modern era, a lone actor doesn’t need to possess the skills or capabilities of an elite unit like Israel’s Kidon, a shadowy subgroup of Mossad, which is believed to conduct assassinations with expertise and impunity. 

Although improvised firearms can be prone to malfunction and are therefore poorly suited for use in mass killings, they are reliable enough for attacks against a single victim. Such weapons therefore pose a grave threat to high-profile individuals and their security details. This is true even in countries like Japan, where gun access is difficult and security measures are tailored to counter lower-tech threats like clubs and bladed weapons.

It remains to be seen how Abe’s assailant learned to build the weapon he used in the attack. It is possible he found instructions online, where how-to guides are readily accessible. Proliferation of online guides and the availability of prefabricated and 3-D-printed weapons parts allows individuals in countries like the U.S. to craft weapons that are far more sophisticated than the one used to kill Abe. These manuals often circulate in extremist online communities, where the ability to fashion one’s own weapons is seen as a crucial element in resisting perceived government oppression. Showing off homemade weapons on niche internet platforms has evolved into its own specific aesthetic, but there are also extremely practical reasons for an uptick in this trend. Improvised weapons obviate the need to purchase or obtain weapons for an attack, thus making violent plots more difficult to detect and improving operations security for the conspirator.

Given the evasive nature of such weapons, violent extremists have shown particular interest in self-made firearms. In the aftermath of an October 2019 terror attack in Halle, Germany, authorities discovered that the gunman had used a DIY weapon made of steel, wood, and 3-D-printed plastic. Further, the attacker’s manifesto expressly referenced his desire to “prove the viability of improvised weapons” and inspire other extremists to follow suit. And in May of this year, after a white supremacist gunman killed 10 people in a racist massacre at a Buffalo, New York, supermarket, authorities discovered that the attacker had posted a manifesto online—a portion of which was dedicated to memorializing the “how-to” aspects of the attack. 

Transmitting or passing on technical know-how following an attack is an increasingly common tactic of violent extremists across the ideological spectrum. Islamist extremists did this for years, including through martyrdom tapes that at once threatened and propagandized. Videos and photographs of the attack and the makeshift weapon used in the attack have already been spread on numerous fringe websites and message boards online. In many cases, terrorist attacks that feature the use of an improvised weapon are scrutinized on sites like 8kun, where the site’s users analyze the weapon and grade it on appearance and utility, while also pointing out to other users how to obtain the materials needed to construct similar devices. 

The Abe attack will likely serve as a source of inspiration to other extremists, whether through so-called copycat attacks or among the broader community of accelerationists, who publicly celebrate high-profile violent attacks. So while the attacker himself had no known connections to accelerationism, the fact that the target was an influential former prime minister of a G-7 country contributes to the overall anarchy that many online extremists vociferously advocate for and seek to create. The attacker’s motive was reportedly linked to his anger over a religious group that he believed had defrauded his mother, and he believed that Abe had ties to this religious group in Japan. As mentioned in Bloomberg, “some of the allegations are reminiscent of the conspiracies spread by QAnon, which has gained traction in Japan.”

The diffuse and elusive nature of the danger posed by DIY weapons complicates the task of countering the threat for law enforcement and intelligence organizations. During a meeting with the chief of MI5 on July 6, FBI Director Christopher Wray cited homemade firearms as a key enabler for lone attackers. The rare joint announcement highlighted the importance of international cooperation and information sharing to effectively mitigate the dangers these weapons pose. Domestic regulation, however, will have to form the bedrock for any cross-border cooperation. 

Earlier this year, President Biden announced a long-awaited set of proposed regulations aimed at restricting use of “ghost guns,” or firearms that lack a serial number and cannot be tracked by federal regulators. The new rules, which are expected to go into effect in August, classify firearm assembly kits as “firearms” under the Gun Control Act and subject their sale to federal gun regulations. Previously, “buy build shoot” kits were available for purchase online without requiring a background check—thus allowing an individual to construct an unserialized firearm at home in roughly 30 minutes. 

The White House’s new ghost gun regulations are likely to be challenged in court. But having a legal basis for enforcement is nonetheless a critical step toward limiting the availability of DIY weapons and empowering security services to effectively counter the threat. In the absence of U.S. federal legislation on the issue, these new rules will help stem the tide in the short term.

Prime Minister Abe’s assassination is a tragic reminder that homemade firearms and improvised weapons can be deadly. The high-profile nature of the attack will undoubtedly draw attention to this unfortunate reality, likely entailing an increase in the already growing interest in DIY guns. 

It will also serve as yet another wake-up call for policymakers and law enforcement professionals to continue working to limit the availability of such weapons and to prevent attacks that employ them. This is not an easy task: There are frustratingly few options available for law enforcement organizations and intelligence agencies to effectively mitigate the emerging threat posed by improvised weapons at present.