In 2009, 138 cases involving 142 defendants went to trial in 50 district courts under the lay judge system introduced that year. Of the defendants — all of whom were found guilty — one received a life sentence and 12 others were given prison terms of 15 years or longer. Seventy-two defendants — more than half — received prison terms of between five and 10 years. Nearly 30 defendants appealed their sentences.

A total of 836 citizens served as lay judges in those cases, deliberating alongside professional judges. In reaching their decisions, they no doubt believed in their hearts that the trials were fair and that no false charges were involved. Citizens face an obvious worry with regard to serving as a lay judge: What if someone they deem guilty is actually innocent? Last year, two murder cases received great public attention because new evidence surfaced that shows the people convicted of the crimes are in fact innocent.

In June, the Tokyo High Court ordered a retrial for Mr. Toshikazu Sugaya, who had served 17 years of his life sentence for the murder of a 4-year-old girl in Ashikaga, Tochigi Prefecture, in May 1990. In the original trial, of great influence on the decision to convict were the results of a DNA test that, it is now known, was flawed. A new DNA test showed that bodily fluid found on the victim's underwear was not Mr. Sugaya's.