TOKYO -- Responding to the not guilty ruling in the retrial of former boxer Iwao Hakamada over a 1966 quadruple murder in Shizuoka Prefecture, prefectural police there and the Supreme Public Prosecutors Office on Dec. 26 announced findings confirming improper interrogation techniques in the initial investigation.

Shizuoka Prefectural Police and the country's top prosecutors' office in Tokyo did not, however, conclude that evidence had been fabricated, as was pointed to in the retrial's ruling to exonerate the now 88-year-old man.

This was the first time investigative authorities in Japan have comprehensively reviewed issues surrounding the case, including the way the investigation was handled and the length of the retrial request process.

Hakamada was originally convicted for the June 1966 killing of four members of a family in the Shizuoka Prefecture city of Shimizu (now part of the city of Shizuoka).

The review focused on the appropriateness of the interrogation that forced a confession from Hakamada, whether physical evidence had been fabricated as recognized in the retrial, and the prolonged retrial process, which took nine years after it was first ordered in 2014.

The prefectural police found that Hakamada had been interrogated for an average of 12 hours a day, and that officers had pressured him into a confession by hinting at the possibility his detention would be extended. The investigators even made him urinate in the interrogation room, it was further confirmed. The findings released by the authorities concluded, "We can only say it was inappropriate."

Moreover, noting that visits by defense counsel were held in an interrogation room with audio recording equipment, the findings summarized, "This was gravely illegal. We must take it seriously and, along with deep reflection, use it as a lesson."

The top prosecutors' office also wrote that Hakamada's testimony was not properly heard out because, though he had maintained that he was innocent, investigators spoke to him in a way that insinuated he was already pinned as the culprit to get a confession out of him.

However, neither the prosecutors' office nor the prefectural police recognized fabrication of evidence presented at the retrial regarding the "five articles of clothing." The items were found about one year after Hakamada's arrest in a tank of miso at a miso factory where he had worked, and were used as evidence against him in the original trial where he was found guilty.

The prefectural police said that they took steps to seek new information from the investigators and others from the time, but were unable to verify that fabrication of evidence had taken place.

Regarding the protracted hearings for a retrial, the prosecutors' office found the extended period could have been necessary since there were points of contention which required scientific verification, including DNA and the shade of the blood stains on the five items of clothing.

On the fact that the prosecution submitted an appeal when the Shizuoka District Court decided on a retrial in 2014, the top prosecutors' office stated that the entire process "cannot be considered unjustifiably prolonged."

Hakamada became the world's longest-serving death row inmate after being accused of the murders and sentenced to death in 1968. The Shizuoka District Court in September 2024 declared him innocent in a retrial, and the prosecution declined to file an appeal.

(Japanese original by Kumiko Yasumoto, Hidenori Kitamura and Sakura Iwamoto, Tokyo City News Department)