The National Public Safety Commission has endorsed a set of rules devised by the National Police Agency for properly interrogating suspects. Under the rules, a system for supervising interrogation processes at police stations will be introduced from April 2009. Police headquarters in large prefectures are considering an earlier introduction. It is hoped that the system will prove effective in preventing false charges.

Under the system, a supervisory section will be set up in each prefectural police headquarters and each police station will also have a supervisor, appointed from sections not involved in criminal investigation. He or she will monitor interrogations through a one-way mirror and also check investigation records.

The rule lists six types of behavior that should not be exhibited by investigators. They include exercising direct and indirect force, and saying or doing anything that severely harms a suspect's dignity or causes unease. A limit will be placed on the length of continuous interrogations. If the supervisor finds inappropriate behavior on the part of investigators, he or she can have the chief investigator stop the interrogation, and upon receiving a report, a supervisor of the prefectural police headquarters will start an investigation. Supervisors at police stations and the prefectural headquarters will also act on complaints from suspects. An official from the prefectural headquarters will also visit police stations without prior notice to observe interrogations.

When supervisors and investigators have differing opinions on whether interrogations are appropriate, supervisors from the prefectural headquarters will have the final say.

Even if the new system helps prevent false charges, police should also seriously consider video-taping interrogations on a large scale. The Supreme Public Prosecutors Office has decided to expand the scope of crimes in which interrogations will be videotaped and to do so nationwide. The police should follow suit.