Sadamichi Hirasawa, a Japanese man, was convicted in 1948 in Tokyo for the mass murder of twelve bank employees in Tokyo, on January 26th, 1948. Shortly before closing time, a man calling himself Jiro Yamaguchi entered the Royal Bank, claiming to be an inspector of the Tokyo health-authority. He gave all sixteen present employees a pill and a few drops of liquid. After consuming it, ten employees died instantly, two succumbed later and four made a full recovery in hospital. He was eventually caught by the police due to the Japanese habit of exchanging cards with personal details. The real Dr. Yamaguchi contacted the police, and one of the cards in Yamaguchi's possession was that of Hirasawa. He was identified by one of the survivors as the man who had given them the poison. Hirasawa's defence was based on partial inaccountability , but the court disagreed and Hirasawa was given the death penalty. His solicitors successfully revoked that sentence, because of a Japanese law that forbade people to co-operate in killing themselves (the Japanese still used the gallow at this point, and it was the executed one's weight that made the system effective). He was then given a life of imprisonment. He died in 1987, being over 90 years old.

References

J.H.H. Gaute and Robin Odell, The New Murderer's Who's Who, 1996, Harrap Books, London