A special inspection by Japan's National Police Agency found that DNA evidence was handled improperly in 239 cases at the Saga Prefectural Police [1].

This failure undermines the reliability of forensic evidence used in criminal prosecutions and raises concerns about the potential for suspects to evade justice. The investigation focused on the actions of Takahiro Tominaga, a 43-year-old former employee of the forensic laboratory [1].

The probe, which began in October 2023 [1], examined a total of 643 DNA tests [1]. Investigators identified 20 different types of improper handling, including the fabrication of results, the forgery of documents, and the loss of evidence [1]. Of the 643 cases reviewed, 239 were flagged for inappropriate processing [1].

Officials said that these failures may have resulted in suspects being overlooked in 37 instances [2]. However, the National Police Agency said that no wrongful arrests were confirmed as a result of the fabrications [2]. A team of 35 experts from the National Police Agency and the National Research Institute of Police Science conducted the inspection to determine the extent of the damage [1].

Tominaga expressed regret for his actions through his legal representative. "I am deeply sorry that there are doubts about the appraisals," Tominaga said [2]. He added that he is reflecting on his conduct [3].

The National Police Agency launched the special inspection to restore public trust and verify whether the integrity of ongoing or closed investigations had been compromised [1]. While the agency confirmed that the fabrications were carried out individually by Tominaga, the scale of the errors suggests a lack of oversight within the laboratory's internal verification processes [1].

“DNA evidence was handled improperly in 239 cases at the Saga Prefectural Police.”

The fabrication of forensic data by a single employee indicates a critical vulnerability in the chain of custody and quality control within regional Japanese police laboratories. While the absence of wrongful arrests prevents immediate legal catastrophes, the fact that dozens of suspects may have evaded capture due to forged evidence damages the perceived infallibility of DNA profiling in the Japanese judicial system.