Abuses by Japan's thought police during World War II belong in history, and so does the so-called Yokohama Incident in which special police in Kanagawa Prefecture arrested more than 60 editors and journalists on suspicion of plotting to revive a communist party. About half of them were indicted and found guilty. The incident, however, remains a subject of legal controversy, as illustrated Tuesday when the Yokohama District Court decided in favor of a retrial.

Many of the defendants were convicted shortly after the end of the war under the Peace Preservation Law, a 1925 statute that prohibited antiestablishment activities. The court gave the green light for a retrial on grounds that the law effectively lost its validity on Aug. 14, 1945, when Japan accepted the Potsdam Declaration to end the war. Prosecutors had contended that the law remained effective until it was repealed by an Imperial rescript in October 1945.

This is the first time that a court of law has decided in favor of a retrial on legal grounds -- namely, that relevant legislation was misapplied. The decision is based on the judgment that the defendants were convicted under a law that had already become ineffective. Past retrials -- including those involving a number of death-row convicts -- have been conducted mainly for reasons of misjudgment.