The Utsunomiya District Court on Wednesday began a retrial of Mr. Toshikazu Sugaya, who had served 17 1/2 years of a life sentence in prison for killing a child until he was released in June on the strength of a new DNA test.

Merely restoring Mr. Sugaya's honor, however, should not be the sole purpose of the retrial. The court should also strive to clarify all mistakes made by the police, prosecutors and the court during the life of this case.

Told the results of a DNA test in December 1991, Mr. Sugaya confessed to the 1990 murder of a 4-year-old girl in Ashikaga, Tochigi Prefecture, and was arrested. But it is now clear that the original DNA test was flawed. The court should find out why the investigators put so much faith in the reliability of that test.

During his first trial, which started in the Utsunomiya court in February 1992, Mr. Sugaya initially admitted to the murder charge, but later denied it before admitting to it again. It is crucial that the court determine what events led him to make false confessions in the first place.

The court has ordered the prosecution to submit a tape recording (15 cassettes) of police and prosecutors' interrogations of Mr. Sugaya in connection with two other, unsolved cases in which a 5-year-old girl was killed in 1979 and another girl of the same age was killed in 1984. It is known that, although Mr. Sugaya denied involvement in all three cases, a public prosecutor, using results of the first DNA test, pressed him to accept the charge of murdering the Ashikaga girl. He did so in tears.

For the current retrial, the defense counsel has called on the court to replay the tape recordings and to allow questioning of the public prosecutor who pressed Mr. Sugaya to confess.

The court should delve into errors committed not only by the investigators but also by the courts. The Supreme Court in 1997 turned down a request by the defense counsel for a new DNA test, and the Utsunomiya court rejected a request for a retrial in February 2008 without carrying out a new DNA test. In the retrial, the court should leave no stone unturned in its effort to identify all mistakes made by authorities, and their cause.