Claim The perpetrators were never identified.
Timeline beat 1984–89 — Aum founded and expands
They were arrested, tried, sentenced and, in the capital cases, executed. Status is convicted.
Darker cells mean a higher score for this topic on that metric.
Notoriety90
Mystery18
Scale85
Evidence88
Legal impact86
Culture80
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Aum’s religious-corporation status was revoked.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.
The subway morning is one date. The investigation file starts earlier and ends in 2018.
English timelines that begin on 20 March miss why police already had a suspect group.
Timeline
JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
- Aum founded and expands
Matsumoto Chizuo’s movement takes the Aum name, gains religious-corporation status and builds communes.
- Sakamoto family murders
Lawyer Tsutsumi Sakamoto, his wife and child are killed. The crime is later tied to Aum and becomes part of the same trial universe.
- Matsumoto sarin
Eight people die in a residential chemical attack later attributed to Aum — the first dated sarin crime in the file.
- Tokyo subway attack
Five trains are attacked during the morning rush. Twelve deaths are first announced; the official count later becomes 13.
- Nationwide raids
Police enter Aum facilities, including Kamikuishiki, and begin mass arrests.
- Asahara arrested
The founder is taken into custody. Religious-corporation status is later revoked.
- Religious Corporations Act revised
Parliament strengthens scrutiny of religious juridical persons after the Aum case.
- Organisations-control law
A statute aimed at groups that have committed indiscriminate mass murder creates ongoing surveillance powers.
- Asahara sentenced, appeals end
A Tokyo court imposes death in 2004; the Supreme Court rejects the final appeal in 2006.
- Executions begin
Asahara and six other Aum convicts are executed; further hangings follow that month after the last related appeal.
Claim versus timeline
Each public-record claim on this dossier sits beside the timeline chapter already on the page.
Public-record encyclopedia. Not legal advice, not a how-to, not a private file.
Claim The attack was an act of war by a foreign state.
Timeline beat Nov 1989 — Sakamoto family murders
Courts found a domestic group’s crime. It is not a wars-app case.
Claim Exactly twelve people died, full stop.
Timeline beat 27 Jun 1994 — Matsumoto sarin
Twelve was the first official figure. A 2008 survey made 13 the standard count; a 2020 death has been recorded as a fourteenth.
Claim Aum appeared from nowhere on 20 March.
Timeline beat 20 Mar 1995 — Tokyo subway attack
Matsumoto 1994 and earlier murders were already in investigators’ orbit. The subway attack was a second chemical crime, not a debut.
Beat weight marks
Mark each timeline beat already on this dossier as supported, contested or unknown, using the public-record claims already filed here. Not a verdict.
Editorial marks on this device only. Public-record encyclopedia — not legal advice, not a how-to, not a private file.
| Timeline beat | Supported / Contested / Unknown |
|---|---|
| 1984–89 — Aum founded and expands Claim already on file: The perpetrators were never identified. | |
| Nov 1989 — Sakamoto family murders Claim already on file: The attack was an act of war by a foreign state. | |
| 27 Jun 1994 — Matsumoto sarin Claim already on file: Exactly twelve people died, full stop. | |
| 20 Mar 1995 — Tokyo subway attack Claim already on file: Aum appeared from nowhere on 20 March. | |
| 22 Mar 1995 — Nationwide raids Claim already on file: Aum appeared from nowhere on 20 March. | |
| 16 May 1995 — Asahara arrested Claim already on file: Aum appeared from nowhere on 20 March. | |
| Dec 1995 — Religious Corporations Act revised Claim already on file: Aum appeared from nowhere on 20 March. | |
| 1999 — Organisations-control law Claim already on file: Aum appeared from nowhere on 20 March. | |
| 2004–06 — Asahara sentenced, appeals end Claim already on file: Aum appeared from nowhere on 20 March. | |
| 6 Jul 2018 — Executions begin Claim already on file: Aum appeared from nowhere on 20 March. |
After July 2018 the lead defendants are dead. Successor-group watch is the remaining state file.
Public-record encyclopedia. Not legal advice. Not a how-to. Graphic detail is withheld. Wars belong in a separate atlas.