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CASE FILE 004

The Teigin Incident

帝銀事件

Poison, postwar Tokyo, a death sentence, and a question that never closed. On January 26, 1948, a mass poisoning and robbery at a bank branch in Shiinamachi became one of Japan’s most disturbing justice-history cases.

Date: January 26, 1948 Place: Shiinamachi, Toshima Ward, Tokyo Type: Mass poisoning / robbery / justice history Status: Conviction with enduring doubts

Editorial Promise

The Teigin Incident is not only a crime file. It is a justice file: poison, public authority, confession, conviction, death penalty, retrial efforts, and the limits of certainty.

SHIMBUN.co.jp does not treat this case as a simple “who did it?” mystery. We do not declare Sadamichi Hirasawa guilty or innocent by editorial instinct. This page separates the crime, the judgment, the doubts, and the unknowns.

CONFIRMEDOn January 26, 1948, a poisoning and robbery occurred at the Imperial Bank Shiinamachi branch in Tokyo. Twelve people died.
CONFIRMEDSadamichi Hirasawa was arrested, convicted, and sentenced to death.
DISPUTEDWhether Hirasawa was the true culprit, and whether the confession and evidence were reliable, have remained disputed.
UNKNOWNThe full truth of the poison, its source, the perpetrator’s skills, and the possible wartime-research context remains debated.
Archival-style image of the Imperial Bank Shiinamachi branch
The bank was a space of trust. The crime entered through the appearance of public authority.

The Shape of the Case

On January 26, 1948, a man claiming to be connected to public-health work entered the Imperial Bank Shiinamachi branch in Tokyo. He reportedly explained that preventive medicine was needed because of a disease scare, and bank staff and others ingested liquid presented as medicine.

Many collapsed. Twelve died. Money was stolen. The incident became one of postwar Japan’s most notorious poisoning-robbery cases.

The crime did not begin with a weapon. It began with trust: a supposed official, a public-health explanation, and a bank willing to obey authority.
Poison and deception evidence still life for the Teigin Incident
Poison and deception. The instrument of the crime was not only chemistry, but authority.

Why It Belongs as Case File 004

Case 001 was the perfect-crime heist. Case 002 was corporate extortion and media fear. Case 003 was a modern forensic cold case. Case 004 is different: the Teigin Incident asks what happens when the state, the court, and public memory cannot fully agree on what justice proved.

Hirasawa was convicted and sentenced to death, but he continued to maintain his innocence. He died in prison in 1987 without execution. The case continued through retrial efforts, public debate, and research into poison, wartime science, and postwar investigation.

Four archive axes

1Mass poisoning and robbery
2Deception through public-health authority
3Hirasawa’s conviction and death sentence
4Retrial efforts and the question of wrongful conviction

Map of the Teigin Incident in Shiinamachi, Tokyo
Map of the incident. Shiinamachi, Toshima Ward, Tokyo, 1948: the geography of a postwar city and a bank branch at the edge of trust.

Timeline

The Teigin Incident did not end on the day of the poisoning. Its timeline runs through investigation, arrest, conviction, death sentence, retrial requests, and a justice question that still has not fully disappeared.

Jan. 26, 1948
A man enters the bank
A man claiming public-health authority arrives at the Shiinamachi branch.
Same day
Poisoned medicine
Liquid presented as preventive medicine is administered to bank staff and others.
Shortly after
Cash stolen
After people collapse, money is taken from the bank.
1948
Sadamichi Hirasawa arrested
The artist Sadamichi Hirasawa is arrested as a suspect.
Trial years
Conviction and death sentence
Hirasawa is convicted and sentenced to death.
1987
Death in prison
Hirasawa dies in prison without execution.
Present
The question remains
The crime, evidence, confession, poison, and postwar context remain subjects of debate.
Timeline of the Teigin Incident
One day of crime, decades of doubt. The Teigin Incident is both a crime record and a justice record.

Media, Memory, and Justice

The Teigin Incident lived through newspapers, radio, courtroom reporting, books, films, research exhibitions, and retrial movements. Each layer changed how the public understood Hirasawa, the police investigation, and the court’s certainty.

The key archive rule is simple: what was reported is not always what was proven. What was judged is not always what stopped being questioned.

Media and memory collage for the Teigin Incident
Media and memory. The Teigin Incident remains in Japan’s crime history because it also remains in Japan’s justice history.

Source Notes

This page is built from public historical materials, reporting, and research institution material. Claims that cannot be fixed are treated as disputed or unknown.

  • Public historical and research materials on the Teigin Incident
  • Meiji University Noborito Institute for Peace Education Museum materials and lectures related to the Teigin Incident
  • Reporting on the crime, trial, conviction, retrial efforts, and Hirasawa’s death in prison
  • Publicly available materials on wartime poison research and postwar justice debates
JUSTICE HISTORY, NOT SUSPECT FANTASY