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.