 Following the discovery of his body, the media offered conflicting explanations involving suicide and murder, while the police did not publicly report the results of their investigation, which was then ended.The Mitaka incident, the Matsukawa derailment, and the Shimoyama incident occurred within one month of one another, and together are known as JNR's Three Big Mysteries.Sadanori Shimoyama, bureaucrat of Ministry of Transport (former Ministry of Railways), was appointed the first president of JNR when it was established on June 1, 1949.