Ex-Saga police technician found to have mishandled 239 DNA tests

TOKYO — A former Saga prefectural police technician mishandled DNA tests in 239 cases, including 37 in which proper analysis might have helped identify suspects, Japan's police agency said Thursday.

The finding was from a special inspection by the National Police Agency of 643 tests handled by Takehiro Tominaga, 43, a former DNA analyst at the Saga police crime laboratory. The NPA revised up the number of cases from the 130 confirmed by Saga police earlier.

The inspection found 20 types of misconduct, including failure to conduct required tests and preparation of false documents, the agency said, adding that some cases involved more than one type of irregularity. Tominaga began carrying out DNA tests in July 2015 and the cases of misconduct date from August 2016.

Tominaga was dismissed in September last year and indicted without arrest in February on charges including creating and using false official documents and destroying evidence. He told the prefectural police he wanted to make his superiors think he had completed his work quickly.

The police agency said his workload was one factor behind the misconduct and will instruct police forces nationwide to carefully assess whether DNA testing is needed before requesting it.

Of the 37 cases, 27 remain under investigation, while the statute of limitations has expired for the other 10, according to the agency. No cases posed a risk of wrongful accusation, it said.

An agency report said Saga police had not fully examined the misconduct, resulting in an incomplete initial count, but added that the unprecedented and highly technical investigation was difficult for the prefectural force to handle alone.

The report said crime labs are sometimes asked to run DNA tests even when suspects have already been identified through other evidence, adding to staff workloads.

The misconduct surfaced in October 2024, when a supervisor found irregularities. Saga police revealed it in September last year, and the police agency launched a special inspection the following month.

© KYODO