The Kabutoyama case, an unprecedented trial in which a former nursery school teacher has stood in the shadow of suspicion for a quarter of a century over the death of one of her mentally disabled charges, is an open invitation to harsh criticism.

Satoshi Kamata, a journalist covering social issues, said the more than 21 years Etsuko Yamada, 48, has spent as a defendant are irrevocable.

The Osaka High Court on Wednesday found Yamada not guilty of murdering one of her pupils in March 1974 at Kabutoyama Gakuen, a former facility for mentally disabled children in Nishinomiya, Hyogo Prefecture. Her indictment was first handed down 21 years ago.