The Supreme Court has upheld the death sentence handed down by lower courts to Tsutomu Miyazaki, 43, who was charged with kidnapping and murdering four young girls in Saitama Prefecture and Tokyo 17 years ago. The highest court concluded that the original judgment recognizing Miyazaki's legal competence was appropriate.

It was a case that sent shock waves throughout Japanese society and gave rise to the term "otaku" (freak or nerd). With the Supreme Court's ruling, the court debate about whether Miyazaki should be held criminally responsible has come to an end. But despite the fact that the court case lasted 16 years, the mystery of Miyazaki's dark mind remains.

The case thus leaves behind a weighty question: How can similar crimes be prevented? Experts in various related fields, including psychiatry and criminal policy, must now take on the difficult task of carrying out a detailed analysis of the case and coming up with proposals for effective preventive measures.