The Reasoning Visualization Model for Rational Crime Analysis and Fact Finding - A Study on Error Detection of Reasoning in Fact Finding

A judge and an investigator use reasoning to investigate a criminal fact in a criminal case. However, reasoning always contains errors due to limitation of their cognitive abilities and restrictions in working. Purpose of this study is to detect an error of reasoning occurring in fact finding of a criminal fact and to suggest a visualization model to find a reasonable fact discovery. This study aimed to apply reasoning visualization model to an actual case and then, to review whether it was possible for a visualization model to clearly reveal reasoning part of fact judgment to detect an error. The case used in this study was a murder case which actually happened as follows; the defendant (husband) came back home and found a victim (wife) who lay in a bathroom with an unusual position, and the defendant reported it to the police. The Issues of this case is cause and time of death. Cause of death was the issue whether the victim was dead by manual strangulation or by positional asphyxia; and, time of death was the issue whether the victim was dead before the defendant went to the office. Issues on the cause of death used in this study were 10 while issues on the time of death were 3. Considering possible manual strangulation, quarrel, and others, the court made a comprehensive judgment on the cause of death while it made a comprehensive presumption by taking into circumstantial evidence, trustworthiness of testimony of the defendant, and others. This study summarized evidence and reasoning part specified in the written judgment (first trial) as a theme of one sentence, and it visually expressed the theme by applying the model of this study. And - 89 it closely reviewed reasoning and evidence used in fact finding. According to analysis of written judgment, it seemed that 9 out of 10 causes of death adopted by the court as evidence of guilt had room for doubt about judgment of guilt. Furthermore, with respect to 3 evidences among 9, the court dismissed defendant's claim through common sense or simple claim but acknowledged them as evidence of guilt. The court dismissed claims of guilt regarding 2 issues of death time issues pursuant to objective reasons; it acknowledged 1 issue of guilty claim but it is thought that there still remains room of doubt. Result of this study implies that visualization model of the study clearly expresses reasoning used in fact finding of fact finder so that it can help detection of reasoning error. Finally, it discussed subsequent researches on meaning and limitations of this study and development of visualization model.