測謊於刑事司法審判上之運用－－兼論測謊於證據法上之評價

Application of polygraph in criminal justice trial--and evaluation of polygraph in evidence rules

系所名稱：犯罪學研究所 學位別：碩士 畢業學年：96年 指導教授：吳景芳 為瞭解測謊於我國地方法院刑事審判上運用之情形，遂利用司法院網站法學資料檢索系統，「地方法院裁判書」查詢，以關鍵字「測謊」為蒐尋對象，限縮查詢範圍為「刑事裁判類」，期間為93、94、95年度三年，故刑事判決書內凡出現「測謊」字樣者，即作為研究對象。經實證研究發現，三年來地方法院採信測謊結果，認有證據能力者高達70.8％，因此判決被告有罪者高達42.6％；而地方法院不採信測謊結果，因而認無證據能力者，則僅29.2％，因此判決被告無罪者，亦僅為18.3％；由以上數據比例研究分析結果，法院仍大部分採信測謊結果，是測謊於刑事司法審判上運用，足以看出仍佔有一席重要地位，尚不容小覷。然測謊係國家機關透過測謊儀器之運作與施測者之分析、判讀，以得知被告所知、所思之內在意思歷程，而作為被告有罪與否之判斷依據。該此被告測謊過程中，其個人思想自由及意思決定之控制能力，已遭剝奪、箝制，被告將被迫違背自己之意思而承認犯罪事實，應認屬不正訊問，尚可認測謊等同非任意性自白外，洵已侵害被告之「緘默權」，更已違反憲法保障「被告不自證已罪」（Privilege Against Self-incrimination.）之基本權利。從證據排除法則立法政策及憲法論言，測謊結果於證據法上，誠應評價為無證據能力，測謊至多僅得作為偵查手段與辦案之參考；如此方能確保被告刑事訴訟法賦予之緘默權及落實憲法保障被告之基本權利。但為了順應世界各民主法治國以科學證據斷案之趨勢，避免阻礙我國科學辦案之發展與進步，測謊結果為法院採為證據，洵已無法避免；然測謊關係是否侵害被告之緘默權及憲法保障被告不自證已罪之基本權利，殊不能僅以最高法院判決或判例為測謊之規範與依據，誠應本於「法律保留原則」、「比例原則」，將測謊相關之程序、要件、目的、用途、效果、證據能力、證明力及有關救濟，透過立法程序，將之具體法律「明文化」，如此偵審機關始有測謊法源依據，被告之人權方能受到保障。

In order to evaluate the application of polygraph in criminal justice trial in domestic district courts, the study method was to search the internet with the keyword of “polygraph” appearing in the “decisions by district courts” limited to “criminal decisions”, by using the law and regulations retrieving system of Judicial Yuan of Republic of China from the year of 2004 to 2006. Therefore, the study materials included the “criminal decisions” with keyword of “polygraph”. The evidence-based study during the 3 years found that the district courts considered 70.8% polygraph results to have evidentiary effect and brought in a verdict of guilty in 42.6% defendants with adopting the polygraph results; in the other hand, 29.2% polygraph results were considered to have no evidentiary effect and a verdict of no guilty was made in18.3% defendants. The results of our study showed that most the polygraph results were adopted by the courts, and therefore, polygraph play a significant role in criminal justice trial.However, polygraph is to try to explore the awareness and thinking of defendants by analyzing and interpreting the polygraph results through a polygraph instrument delivered by the officers, and the polygraph results might be the evidentiary of a verdict. During the process of polygraph, the individual freedom of thinking and control of determination have been deprived and limited, and the defendant would be forced to confess the crime against the defendant’s own will. Therefore, in addition to an unjustifiable interrogation and an involuntary confess, the polygraph might invade the privilege of silence and violate the basic right of privilege against self-incrimination under the protection of constitutional law. Based on exclusionary rule and constitution law, the results of polygraph should be considered to have no evidentiary effect, and the polygraph should be, at most, a reference of criminal investigation; under these considerations, the privilege of silence proved by criminal litigation law and violate the right of privilege against self-incrimination under the protection of constitutional law.