An article linked in another comment in this thread[1] implies that this is because Japanese prosecutors pressure everyone, even innocents, into confession[2].

An article linked in another comment in this thread[1] implies that this is because Japanese prosecutors pressure everyone, even innocents, into confession[2]. [1] https://news.ycombinator.com/item?id=27827906 https://news.ycombinator.com/item?id=27827906 [2] https://www.nytimes.com/2007/05/11/world/asia/11japan.html https://www.nytimes.com/2007/05/11/world/asia/11japan.html