Thorough investigations into the causes of wrongful convictions are imperative

In March 26, Toshikazu Sugaya, the accused in the Ashikaga Case in which a 4-year-old girl was kidnapped and murdered, was acquitted by the Utsunomiya District Court in a retrial. Though this proved his innocence, the fact remains that he spent 17 and a half years behind bars.

In the previous (conclusive) trials of the Ashikaga Case, Sugaya was convicted based primarily upon the DNA test results and his confession. However, a far more accurate DNA test method (called the STR method) has recently demonstrated that the DNA patterns of the real criminal are different from those of Sugaya, which aroused doubts as to the credibility of his confession and subsequently led to a not-guilty ruling in the retrial. In response, the mass media reported that the causes of the wrongful conviction in this case were the overrating of the conventional DNA test method (called MCT 118 method), which was a lower-accuracy method typically used at the time of Sugaya's arrest, and the overemphasis placed on his confession. Pointing out these problems in the abstract, however, does not help prevent wrongful conviction. The National Police Agency and the Supreme Public Prosecutors' Office made public a report on the causes of the wrongful conviction, while the Japan Federation of Bar Associations submitted a request in writing to establish a third-party organization for examination. Though the results of the examination should be thoroughly reviewed to look into the real causes of this incident, there already appear to be some problems associated with the police's investigation and trials.

Were the results of the conventional DNA test method admissible as evidence?

The MCT 118 method, on which Sugaya's conviction in the previous trials was based, is far less accurate than the newly introduced STR method. In fact, combined with other conditions such as blood type, the MTC 118 method can identify a DNA pattern at a ratio of 1.2 out of every 1,000 people. This means that there were about 50 men with the same DNA pattern in the city of Ashikaga where the incident occurred. On the other hand, the STR method can identify a DNA pattern at a ratio of one out of every 4,700 billion people. This indicates that the MCT 118 method can only identify a DNA pattern with significantly diminished accuracy. Nevertheless, we cannot say the DNA test results according to the MCT 118 method should not have been used as evidence based solely on its level of accuracy. In fact, before the STR method was developed, it was accepted that 1.2 out of every 1,000 people was accurate enough for identifying a DNA pattern, and these DNA test results had sufficient evidentiary to be regarded as one factor in deciding a conviction.

(Besides this accuracy issue, there is an argument that errors may have been made in conducting the DNA tests themselves in the Ashikaga Case. The Utsunomiya District Court did not admit the DNA test results as evidence because doubt remained as to the identification (of DNA patterns). This judgement is different from that of the Supreme Court in the previous trials. If the case were appealed to a higher court, this argument would be discussed further. Thus, the issue has not been settled yet, in a sense.)

How should they have judged the credibility of Sugaya's confession?

Of course, no DNA test result according to the MCT 118 method can prove a defendant's guilt beyond the reasonable doubt by itself. Combined with other evidence, DNA test results can be used to find a person guilty or not guilty. In the Ashikaga Case, the other evidence is Sugaya's confession. If his confession were highly credible, it would be possible to bring in a verdict of guilty based on the MCT 118 in spite of its lower accuracy. Though, in general, a decision about whether confession is credible or not is based on the consistency, details, and reality of the confession, the correspondence of the confession with objective evidence is also important. However, there was little evidence to corroborate Sugaya's confession. For example, nobody saw a bicycle in the place where Sugaya, according to his confession, had parked his bicycle with the little girl as a passenger. Also there was no record of a receipt at the supermarket where, according to his confession, Sugaya had bought canned coffee and rice balls after the murder. In spite of these inconsistencies, both police and prosecutors reached the conclusion that Sugaya was the criminal, and then the court brought in a verdict of guilty. This implies that they overrated the DNA tests and placed too much credence in his confession. Both the Constitution of Japan and the Code of Criminal Procedure require corroborative evidence for confessions partly so as to judge the credibility of confessions objectively. Toward these ends, we need fair administration of laws.

Enhanced defense in criminal procedures is a must

In the retrial of the Ashikaga Case, the tape recordings of a part of the interrogation process by the prosecutors were replayed in court. Some claim that recording of the interrogation process will enhance visibility and help prevent wrongful or coercive interrogations and eliminate the possibility of false confessions. However, as far as the tape recordings replayed in the retrial are concerned, the interrogation process does not seem so coercive. Nevertheless, Sugaya admitted to the crime though he had denied it at the beginning of his interrogation. I think it is difficult to find that Sugaya's confession during the interrogation process is false at a stage where the difference of DNA patterns between Sugaya and the real criminal was not found.

Also in the Ashikaga Case, Sugaya confessed during the interrogation process, and continued to confess to the crime in court until he was questioned there, almost at the final stage of the trial. If he had denied the charges earlier, the situation would have been different. The defense lawyer in the first trial regretted not having built a relationship of trust with Sugaya, which might have allowed him to recognize that Sugaya's confession was false. This is a crucial point, considering the fact that only lawyers can defend the interests of and the accused in criminal procedure. Fortunately, from 2006 suspects have the right to appointed council for certain serious offenses. In order to further enhance the defense in criminal procedures, lawyers should meet the defendant repeatedly to give him the opportunities to consult with them, form a relationship of trust, determine whether the confession of the accused is at all dubious at an early stage, and persuade the accused to deny his confession if it is found to be false.

Click here for the culture program Corridor of Knowledge (Citizen Judge System-Citizen Participation Changes the Judiciary, Episode 73), edited by the author