Six former members of the AUM Shinrikyo cult, who were on death row over the deadly sarin gas attack on Tokyo's subway system in 1995 and other crimes, were executed on July 26. The move completes the punishment of all relevant convicts, including former AUM leader Shoko Asahara, whose real name was Chizuo Matsumoto.
But this is not the time to forget about the AUM cases. The cult intended to topple the state, and carried out a chemical terror attack using a nerve agent. Why were such large-scale acts of terror planned and carried out? The question has not received a full answer.
There are many unresolved components in AUM-related cases. The statute of limitations was reached over the shooting of the National Police Agency chief leading an investigation into the cult. A former police officer, who was a follower of the cult, was arrested in the case, but he was not indicted. Reasons behind such failures in AUM-related investigations have not been sufficiently examined.
The truth was sought in criminal trials on the subway attack and other cases. But the evidence presented in courts is limited. Painting a complete picture about what happened based on trial records is no easy task.
A variety of organizations, such as police, the prosecution, the Public Security Intelligence Agency and the Self-Defense Forces, must have independently collected information, but little has trickled out into the public domain.
The AUM cases claimed 27 lives and injured more than 6,000 people. These are unprecedented crimes. The government must consolidate all relevant information and produce a report as lessons learned for future generations. Records held by the private sector, including the subway operator Teito Rapid Transit Authority (now Tokyo Metro), should be incorporated into the report as supporting documents.
A think tank in the United States compiled a report on the sarin subway incident seven years ago. It examined how AUM developed biological and chemical weapons. For the report, a former chief of the U.S. Navy and others conducted more than 20 interviews with former AUM cultists who were hanged this July, among others. They made a detailed analysis on how AUM, despite repeated mistakes, came to acquire chemical weapons, and made their findings public.
Such an effort is required as a means of counterterrorism, which is looming as one of the most important issues ahead of the upcoming Tokyo Olympics and Paralympics in 2020. Lessons learned in response to AUM cases must be reflected in such preparations.
When producing a report, the government must also explain why the two sets of executions were carried out in July, hanging an unprecedented number of 13 death row inmates in a short period of time. And the report must shed light on the internal discussions that took place regarding how to proceed with the hangings.