Institute at top court warns against over reliance on DNA tests
JIADEP Note: I'm not really sure what this means. Perhaps the Supreme Court worries that criminals may go free if no scientific evidence is available for coroboration.
December 27, 2012(Mainichi Japan)

A Supreme Court research institute has warned against over-reliance on DNA and other scientific evidence, and compiled guidelines for handling such evidence.

In a report released on Dec. 26, the Supreme Court-affiliated Legal Training and Research Institute of Japan pointed out that scientific evidence would not serve as a decisive factor in identifying a defendant as a criminal, while admitting that such evidence leads to greater objectivity. The report warned that excessive focus on science and its powerful capacity to underpin physical evidence risks distorting fair judgment, and stressed the need to evaluate all evidence comprehensively.

The report was compiled by a team of three judges and a DNA testing expert. The team had been working on the subject since the 2010 acquittal of Toshikazu Sugaya in a murder retrial, which stirred criticism that overreliance on DNA tests had led to false convictions.

While acknowledging that scientific evidence allows prosecutors to break a tendency to rely on confessions, the report said it constitutes only one type of circumstantial evidence. The report furthermore stated that DNA testing can only be used to build a case against a suspect when combined with other evidence, such as witness depositions and how DNA samples were found at the crime scene.

If the credibility of scientific evidence itself becomes a point of contention in lay judge trials, technical knowledge to be presented during hearings should be kept to a necessary minimum and be explained in plain language, the report said.

Specifically, both the prosecution and defense parties should make their cases while being well aware of the roles and limits of evidence. The report also underscored the need to give enough time for lay judges to sort out their questions during trials.

Meanwhile, the report credited current DNA testing with an unsurpassed capacity to identify individuals, and called for "legitimate testing" including proper storing of DNA samples, rather than further improvement of the accuracy of such testing.