One of the remaining 8 cards was received by Hirasawa. The police were led to arrest Hirasawa because: He could not produce the card he had received from Matsui. Hirasawa claimed to have lost the business card, together with his wallet, due to his having been the victim of pickpocketing. A similar amount of money to that stolen from the bank was found in Hirasawa's possession, the origin of which he refused to divulge. The origin of the money is unknown to this day (though some, such as the crime fiction novelist Seichō Matsumoto, suggested Hirasawa received it by drawing pornographic pictures, a side business that would have been detrimental to Hirasawa's reputation as an artist). Hirasawa's alibi of having been taking a stroll in the vicinity of the crime scene could be neither verified nor substantiated. Hirasawa was identified as the poisoner by several witnesses (but only by two survivors, and see picture below). He confessed to having been involved in four previous cases of bank fraud (recanted together with his subsequent confession). He was arrested on August 21, 1948. After police interrogation, which allegedly involved torture, Hirasawa confessed, but then recanted soon after. His later defence against his confession was based on partial insanity, alleging that he had been troubled with Korsakoff's syndrome (as a result of rabies inoculation) and so his confession was not reliable. The court, however, disagreed and Hirasawa was sentenced to death in 1950. Until 1949, a confession was solid evidence under the law, even if the police tortured a person to extract said confession. The Supreme Court of Japan upheld the death sentence in 1955. His attorneys tried to have the sentence revoked, submitting 18 pleas for retrial over the following years. 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 a former member of 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 conviction with his film Teigin jiken: Shikeishû (Teijin Incident: Condemned / The Long Death) in 1964. Successive Ministers of Justice in Japan did not