Darker cells mean a higher score for this topic on that metric.
LessMore
Last reviewed Sources & creditsMedia creditsMethodology
Quick answers
What happened on 20 March 1995?
Aum Shinrikyo members released sarin on five Tokyo subway trains during the morning rush toward Kasumigaseki. Thirteen people were later counted as official dead (twelve at first; one added after a 2008 survey). Thousands sought medical care. This page does not describe the release method.
Who was convicted?
Asahara Shoko (Matsumoto Chizuo) and a group of senior members were convicted. Asahara’s death sentence became final in 2006; he was executed on 6 July 2018 with other Aum convicts. About 190 members were found guilty in related cases. Status is convicted, not unsolved.
Was this a war?
No. It was a domestic criminal and terrorism case against a civilian transport system. It belongs in an investigations family, not in a wars file.
What was Aum Shinrikyo?
A Japanese new religious movement founded in the 1980s by Matsumoto Chizuo, who took the name Asahara. It mixed Buddhist and Hindu language with apocalyptic teaching and, in its criminal core, organised murders and two sarin attacks. After 2000 the main successor body used the name Aleph.
What was the Matsumoto case?
On 27 June 1994, sarin was used in Matsumoto, Nagano Prefecture, killing eight people. Once linked to Aum, it became the prior chemical crime in the same investigation family as 20 March 1995.
What laws changed?
Aum’s religious-corporation status was revoked. The Religious Corporations Act was revised in 1995. The 1999 Act on the Control of Organizations Which Have Committed Acts of Indiscriminate Mass Murder created ongoing surveillance of successor groups.
Investigation was ordinary criminal procedure at extraordinary scale.
It was not a battlefield inquiry and not a lesson in how to evade police.
Agencies
- Tokyo Metropolitan Police Department — Lead on the 20 March scenes, arrests and the later victim-compensation survey.
- National Police Agency — Coordinated nationwide raids and the merger with Matsumoto and other Aum cases.
- Public Security Intelligence Agency — Pre- and post-trial watch on Aum and successor bodies under later control statutes.
- Tokyo District Court / Supreme Court — Tried Asahara and senior members; finalised capital sentences that were executed in 2018.
What followed
- Treat the wounded, close the lines
20 March was first a mass-casualty medical and transit emergency. Identification of the agent followed the same day.
- Raid the communes
From 22 March, searches at Aum sites produced the physical and documentary core of the case.
- Arrest the founder
16 May 1995 ended the fugitive phase and started the charging clock.
- Join the older files
Sakamoto, Matsumoto and other crimes were tried as one enterprise, not as trivia.
- Litigate for a decade
Death and life sentences accumulated through the 2000s as appeals ran their full Japanese course.
- Watch the successors
After 1999, control-act surveillance replaced the idea that a dissolved corporation was the end.
Turning points
- Matsumoto recognised as Aum — Once 1994 was joined to 1995, the group could not be cast as a one-morning aberration.
- 16 May 1995 — Asahara’s arrest made the case a trial project rather than a manhunt.
- July 2018 — Executions closed the capital docket after the last related appeal.
The investigation is a model of after-the-fact state work. It is not a manual.
Public-record encyclopedia. Not legal advice. Not a how-to. Graphic detail is withheld. Wars belong in a separate atlas.