Sadamichi Hirasawa - Doubt Over Guilty Verdict

Doubt Over Guilty Verdict

He was sentenced to death, but there was originally no conclusive evidence. In addition, although 40 employees saw the crimes, there were only two people who identified him as the criminal. Seichō Matsumoto presumed that the true culprit was Unit 731 in his books A story of the Teikoku Bank Incident in 1959 and The Black Fog of Japan in 1960. Matsumoto also suspected that "the money of unknown origin" came from selling pornographic drawings. Kei Kumai protested Hirasawa's innocence by his film The Long Death in 1964.

Successive Ministers of Justice in Japan did not sign his death warrant, so the death sentence was never carried out. Even Isaji Tanaka, who on 13 October 1967 announced in front of the press that he had signed death warrant of 23 prisoners in one go, did not sign Hirasawa's death warrant, stating that he doubted Hirasawa's guilt.

The poison was regarded as the readily obtainable potassium cyanide in Hirasawa's trial. One of the reasons given to doubt Hirasawa's guilt is because the victims' symptoms were clearly different from potassium cyanide poisoning, which is rapid. Keio University's contemporary investigation claimed that the true poison may have been acetone cyanohydrin, a military poison deliberately designed to be slow-acting, which Hirasawa could not have obtained.