Case overview
On March 20, 1995, members of Aum Shinrikyo released sarin nerve gas across five Tokyo subway trains during morning rush hour, killing 13 people and injuring over 6,000. The coordinated attack exposed a religious group that had spent years building weapons, silencing defectors, and preparing for what its leader called an apocalyptic war.
The organization and its founder
Aum Shinrikyo was founded in 1984 by Shoko Asahara, a partially blind yoga instructor who blended Buddhist and Hindu teachings with apocalyptic prophecies. Asahara claimed he had achieved enlightenment and positioned himself as the only person capable of saving humanity from destruction. By the early 1990s, the group had attracted thousands of followers in Japan and abroad, many of them well-educated professionals drawn to his teachings on meditation and salvation.
The organization operated communes where members lived in isolation, surrendered their assets, and followed strict routines dictated by Asahara. Sleep deprivation, limited food, and repeated exposure to his recorded sermons were standard. Members who questioned leadership or attempted to leave faced threats, physical punishment, or forced confinement. Former members described a system in which loyalty was enforced through fear and the belief that leaving meant spiritual death.
Asahara’s teachings shifted in the late 1980s toward predictions of imminent global conflict. He told followers that governments, particularly the United States and Japan, were plotting to destroy Aum Shinrikyo and that the group needed to defend itself. This narrative provided justification for stockpiling weapons and developing chemical and biological agents.
Escalation into violence
Aum Shinrikyo’s first confirmed killing occurred in 1989, when the group murdered anti-cult lawyer Tsutsumi Sakamoto, his wife, and their infant son. Sakamoto had been representing families seeking to remove relatives from the organization. Members broke into the family’s home, suffocated them, and buried the bodies in remote mountain locations. The murders went unsolved for years.
The group began manufacturing sarin gas in 1993, constructing a lab at a compound near Mount Fuji. Scientists and chemists within the organization worked under Asahara’s direction to produce the nerve agent. In June 1994, Aum members released sarin in Matsumoto, targeting a residential neighborhood where judges presiding over a lawsuit against the group lived. The attack killed eight people and injured over 200. Authorities initially suspected a local resident and did not connect the incident to Aum Shinrikyo.
Internal documents and later testimony revealed that Asahara ordered the attack to disrupt legal proceedings and intimidate critics. The success of the Matsumoto attack, combined with the lack of immediate police response, emboldened the group’s leadership.
The Tokyo subway attack
On the morning of March 20, 1995, five teams of Aum Shinrikyo members boarded separate subway trains on three converging lines in central Tokyo. Each team carried packages of liquid sarin wrapped in newspaper. At approximately 8:00 a.m., as trains filled with commuters, the members punctured the packages with sharpened umbrella tips and exited at the next station. The sarin vaporized as it spread through the cars.
Passengers began collapsing within minutes. Victims experienced blurred vision, difficulty breathing, convulsions, and loss of consciousness. Subway workers and bystanders attempted to remove the leaking packages, exposing themselves to the gas. Emergency responders arrived without protective gear or knowledge of the substance involved, leading to secondary contamination.
Thirteen people died, including two station attendants who handled the sarin-soaked materials. More than 6,000 others sought medical treatment, with over 1,000 requiring hospitalization. The attack disrupted subway operations across Tokyo and prompted evacuations of government buildings and public spaces.
Investigations later confirmed that Asahara had ordered the attack in response to planned police raids on Aum facilities. Authorities had been gathering evidence linking the group to the Matsumoto incident and other crimes, and Asahara believed a large-scale attack would divert law enforcement and delay arrests.
Arrests and prosecution
Police raided Aum Shinrikyo’s main compound in Kamikuishiki on March 22, 1995, two days after the subway attack. Officers found chemical production equipment, stockpiles of materials used in sarin synthesis, and weapons including automatic rifles and explosives. Asahara went into hiding within the compound and was arrested on May 16, 1995, concealed in a small space between walls.
Over the following months, authorities arrested nearly 200 members of the organization. Prosecutors charged Asahara with masterminding the subway attack, the Matsumoto sarin release, and multiple murders. Trials revealed the extent of Aum’s criminal activity, including kidnappings, extortion, and attempts to manufacture biological weapons such as botulinum toxin and anthrax.
The five members who carried out the subway attack received death sentences. Additional members involved in planning, logistics, and prior attacks were convicted on charges ranging from murder to illegal weapons production. Asahara’s trial lasted eight years. He was convicted on 13 counts of murder and other charges in 2004 and sentenced to death.
Testimony and motive
During interrogations and trials, members provided accounts of life inside Aum Shinrikyo and the process by which they were directed to carry out violence. Several described being told the attacks were necessary to prevent a larger catastrophe or to defend the group from annihilation by outside forces. Others testified that they believed Asahara’s orders came from a spiritually enlightened place and that obedience would ensure their salvation.
Defendants expressed varying degrees of remorse. Some acknowledged their actions were criminal and apologized to victims’ families. Others maintained they had acted under duress or had been manipulated by Asahara’s teachings to the point where they could not distinguish moral boundaries.
Psychiatric evaluations examined the role of coercive control within the organization. Experts noted that prolonged isolation, sleep deprivation, and repeated indoctrination created conditions in which members felt unable to refuse orders or question leadership, even when directed to commit violent acts.
Aftermath and executions
Japan’s government designated Aum Shinrikyo a terrorist organization and passed legislation allowing continued surveillance of groups that had committed mass violence, even after leadership changes. The organization formally dissolved and rebranded under new names, including Aleph and Hikari no Wa, while claiming to have rejected Asahara’s violent teachings. Authorities maintained monitoring programs, citing concerns that former members continued to venerate Asahara.
On July 6, 2018, Shoko Asahara and six other members of Aum Shinrikyo were executed by hanging. Seven additional members were executed later that month. The executions concluded more than two decades of legal proceedings and marked the final resolution of the criminal cases stemming from the subway attack.
Victims’ families and survivors have advocated for continued recognition of the attack’s impact. Many continue to experience physical and psychological effects from sarin exposure. Memorial events are held annually on March 20 at affected subway stations.
Where to look next
- Documentary: “A” (Tatsuya Mori)
- Book: “Underground: The Tokyo Gas Attack and the Japanese Psyche” by Haruki Murakami
- Podcast: “Cults” (Parcast Network)
