Police Own Up to Significant Error in Investigation of Ohkawara Kakohki Case
The Tokyo Metropolitan Police Department (MPD) has admitted to a "serious mistake" in its investigation into Ohkawara Kakohki Co., a machinery maker, which led to false accusations against its executives and their subsequent arrest.
The core issue was a dysfunctional chain of command within the MPD's Public Security Bureau, where critical information unfavorable to the case was not shared with senior officials. These senior officials merely rubber-stamped investigation procedures without properly reviewing or checking the evidence.
The investigation, led by a dysfunctional leadership structure that failed to properly communicate or scrutinize evidence among the chain of command, resulted in the arrest of Ohkawara Kakohki's President Masaaki Okawara and two other executives. The police accused them of illegal export of machinery capable of weapons production, but the charges were later dropped by prosecutors before the trial began.
This investigation and arrest caused nearly a year of wrongful detention before the indictment was withdrawn in 2021.
MPD Superintendent-General Yuji Sakoda publicly apologized for causing significant stress and hardship to the accused executives and promised to improve its procedures. He announced the creation of a new office to guide investigations and bolster third-party review of evidence.
Disciplinary action, including pay cuts, was announced for 19 current and former MPD personnel involved. The MPD's apology was made during a news conference on Thursday, August 7.
This serious failure in the investigative process was officially acknowledged in a 2025 report by the MPD following a finalized court ruling that the investigation was illegal, leading to compensation payments to the plaintiffs.
[1] Jiji Press report, August 7, 2025 [2] Tokyo Metropolitan Police Department report, August 7, 2025 [3] Court ruling, May 2025 [4] Prosecutor's decision to drop charges, February 2021 [5] MPD press conference transcript, August 7, 2025
- The MPD's apology for the wrongful accusations and subsequent arrest of Ohkawara Kakohki's executives included a commitment to improve their evidence-sharing policies and procedures in light of the identified chain-of-command dysfunction.
- In order to prevent future miscarriages of justice, the MPD is establishing a new office that will guide investigations and implement rigorous third-party evidence reviews, in accordance with the lessons learned from the Ohkawara Kakohki case.
- The MPD's failure to share critically important information regarding the Ohkawara Kakohki investigation has now become a matter of policy-and-legislation discussion within Japanese politics, with general-news outlets covering the story extensively under crime-and-justice sections.
