A Kobe court has disposed of all its records related to the ruling and investigation into a 1997 serial murder case involving a teenager who killed two elementary school students and attacked three more, an official said Thursday.

While regulations by the Supreme Court state that, generally, records on incidents involving minors should be preserved until the individual reaches the age of 26, documents of historic value must be kept beyond the limit and in perpetuity under special preservation provisions.

The disposal of the documents by the Kobe Family Court, which come from a case that not only shocked the nation but was also a foundational moment in Japan imposing tougher punishments on underage offenders, highlights how criminal incidents and their records of historical significance are treated.