Ashikaga Case

Poor DNA testing and Police



Poor DNA testing and secret design of police

Ashikaga case was the first one in which DNA testing was used as conclusive evidence. In the other words, it was a so-called 'monumental' case in scientific criminal investigation of Japan police force.

On 12th May 1990, a four-year-old girl went missing at Ashikaga city, Tochigi Prefecture and the following morning she was found dead in a river terrace nearby. This is gAshikaga Caseh.

In 1991 when DNA testing was done for Ashikaga case, the testing was able to identify 1.2 persons out of 1,000. The assessment of the matching was done not through computer analysis but only with eyes.

In fact, the DNA testing of Ashikaga case was very poor. It was done in the National Police Agency affiliated organization, that is, the National Research Institute of Police Science. For the testing, two samples were necessary. One was from the body fluid on the victimfs clothes left at the scene of the crime, and another was from the alleged murder suspect.

The former, the muddy victimfs clothes was picked out in the river and then it had been preserved at room temperature, despite it should have been preserved at minus 80 degrees centigrade and should be used within one year. But it was used for the testing after one and a quarter year. In addition, there was only slight amount of fluid on the clothes and it was not nearly enough for DNA testing of the day.
The DNA testing using such a sample as the above was not based on the criteria that the National Police Agency set for DNA testing at the time.

And moreover, the latter sample was from the garbage that the alleged murder suspect Mr. Toshikazu Sugaya put at waste-collection point. A policeman tailing him took it up and it was used for DNA testing even without search warrant.

The National Police Agency themselves seemed to understand that there were such inadequacies in the DNA testing done in their own affiliated organization. But the National Police Agency seemed to leak deliberately the assessment of the DNA typing to some of major newspapers, concealing all the above inadequate process in the DNA testing. Why? Because at the time they wanted to get the budget allocation (116 million yen) for installation of the equipment for DNA testing in every prefectural police department all over the country. They seemed to have an intention to use media for advertising the value of gDNA testing.h
As they expected, the value of the DNA testing was highly publicized and emphasized and then Mr. Sugaya was arrested before issuing arrest warrant. Consequently, the National Police Agency got successfully the budget allocation, which was rejected by the Finance Ministry before.

Forced confession and Testimony fabricated by police

Meanwhile, earlier, at Ashikaga city, in 1979 and 1984, two similar little girl murder cases happened but those remained unsolved. Therefore, police was desperate to arrest the criminal at any cost.

Mr. Sugaya says that police forced a confession to him by their physical violence and threat continuously for many hours and finally he made up a false confession led by police. Moreover, he was forced to confess the earlier two similar murder cases and he made up a false confession about those, too. His confession was not true and naturally it contradicted an important testimony of an eyewitness of the murder case of 1979. According to the eyewitness, in front of the eyewitness, the record of the testimony was changed and fabricated by policemen and the eyewitness was constrained to place a seal on and did so.


The aforementioned assessment of the DNA testing and his made-up confession forced by police were considered as conclusive evidences in all courts. All the defence line was rejected; his proclamation of innocence, discrepancies between his forced made-up confession and facts found at the scene of the crime, and his petition for disclosing the process of the DNA testing and for the DNA re-testing were ignored.
Mr. Sugaya was sentenced to life in prison in Supreme Court on 17th July 2000.

DNA re-testing after 17 years

As already stated, the DNA testing done for Ashikaga case was very poor. Then, also the accuracy of DNA testing has greatly improved, and it is now 1 in 4.7 trillion according to the National Police Agency.
It was 17 years later since the former testing that Mr. Sugayafs petition for DNA re-testing was accepted and the Tokyo High Court ordered DNA re-testing. The DNA re-testing was done by two expert witnesses, one recommended by the defence and another by the prosecution.
On 8th May 2009, both of the expert witnesses proved that Mr. Sugaya was innocent.

On 4th June, after 17 years and half imprisonment, he was released by suspension of his sentence before retrial starts. On 23rd June, Tokyo High Court ordered retrial.

The news about liberation of Mr. Sugaya and the result of the DNA re-testing had a much public response and attention. Local police, the Prosecution and Supreme Court apologised to Mr. Sugaya for their mistakes. Now, he demands transparency in police investigation.

- 15th October 2009 -


On 26th March 2010, Utsunomiya District Court declared Mr. Sugaya innocent and then the bench apologised to him.