A Study of medico-legal experts' opinions on blood type and the possible causes of misjudgment that led to retrial and acquittal in three major Tohoku region cases

1. 研究目的本研究的主要目的是厘清东北地区三起导致再审和无罪释放的重大案件的部分误判原因。这些错误判断是基于医学法律专家的结论。这些案件涉及1949年在广崎市、1952年在青森市、1955年在松山町（宫城）发生的谋杀案。研究结果(a)青森（Yoneya）案：研究表明，很可能在根据被告唾液确定血型时出现了错误，这限制了法医专家意见中证据的可信度。同时，作者预测，当有能力的专家检查足够数量的分泌物样本时，可以获得更高的可信度（尽管准确性是有限的）。(b) Hirosaki案：Y. Watanabe博士的结论是，血液来源和血型的确定，特别是从干渍中测定所谓的Q和E系统血型的确定，是非常值得怀疑的。作者同意这一观点。在此基础上，作者指出了新科学证据的可采性问题的重要性，这一点在弘崎案中得到了很好的说明。(c)松山案：青森案和弘崎案的结果使撰文人有了洞察力，有助于解释此案，并了解法医专家关于血液鉴定的意见的可信性限度。在日本，需要进行理论和实践的联合研究，以消除这三个案例中揭示的误判原因，以及日本各地报道的其他案例。作者希望本研究能为今后对这一问题的研究提供一个先导性的研究。

1. Research purposeThe main purpose of this study is to clarify some of the causes of misjudgment in three major Tohoku region cases that led to retrial and acquittal. These misjudgments were based on conclusions of medico-legal experts. The cases involved murders committed in Hirosaki-shi in 1949, Aomori-shi in 1952, and Matsuyama-machi ( Miyagi ) in 1955.2. Research results(a) The Aomori ( Yoneya ) Case : The research shows a high probability that there was a mistake in determining blood type from the accused's saliva which limited evidential credibility in the medico-legal experts' opinion. At the same time, the writer predicts that higher credibility can be obtained ( though there is a limit on accuracy ) when a sufficient quantity of secretors specimen is examined by competent experts.(b) The Hirosaki case : Dr. Y. Watanabe concluded that the determinations of blood origin and type especially regarding the so called Q and E system blood type from dried stains were quite questionable. The writer agrees with this view. Furthermore, the writer points out the significance of admissibility problems with novel scientific evidence, which are well illustrated in the Hirosaki case.(c) The Matsuyama case : The results from the Aomori and the Hirosaki cases give the writer insight which helps in interpreting this case, and in understanding the credibility limits of medico-legal experts' opinions on determinations regarding blood.3. Application and future workHere in Japan, theoretical and practical joint research is needed to eliminate the causes of misjudgment revealed in these three cases, and in others reported from all over Japan. The writer expresses his wish that the present study would serve as a pilot study for future investigation of this issue.