DNA證據在刑事案件運用之實證研究-以台北、士林、板橋地方法院訴訟轄區為例

Abstract

DNA（deoxyribonucleic acid，即去氧核糖核酸）自1984年英國萊斯特大學(Leicester University)遺傳學家亞力．傑佛瑞(Alec Jeffreys)研究發現可以做為身分辨識之用，將這種方法稱為DNA指紋(DNA Fingerprinting)，並於1986年首次運用在英國發生的強姦殺人案件上。美國亦於1987年在佛羅里達州的一件強暴案件中首次採用DNA鑑識技術，來確認嫌犯的身分。我國則在民國81年4月間，運用DNA鑑識技術在刑事案件上，以確認因槍擊案件現場三具燒焦屍體的身分。我國引進DNA證據作為刑事證據，已將近15年，而DNA證據在我國刑事審判中所扮演的角色如何?係一值得探討研究的課題。

DNA鑑定技術的發現不僅是鑑識科學(Forensic Science)的重大成就，DNA證據高度的個人鑑別功能，更成為刑事案件偵查、審判中發現事實的一項新利器。而DNA證據在引進法庭後，其在法庭上固然扮演著舉足輕重的角色，但DNA證據除了首先須面對的科學證據課題外，由於DNA鑑定技術本質上的問題，例如鑑定方法、檢體及實驗室污染問題、族群遺傳及人口統計資料庫等，使DNA證據在法庭上無可避免的引發一連串的法律爭議。

本文研究綜合文獻分析法、內容分析法、問卷調查法、統計分析法等研究方法。首先採文獻分析法探討DNA的發現及發展史、DNA鑑定的原理與方法、DNA證據在鑑識科學及美國刑事案件上的運用。在實證研究方面，係以台北、士林、板橋地方法院訴訟轄區為研究範圍，以問卷調查法對從事司法實務工作者如法官、檢察官、律師、公設辯護人等進行問卷調查蒐集資料。同時蒐集92年9月1日我國新刑事訴訟法施行前後2年，三個法院以DNA為證據之刑事判決，以內容分析法進行資料分析，最後以統計分析法分析蒐集之資料所呈現的現象，提出研究結論及建議。

British geneticist Alec Jeffreys developed the technique of DNA（deoxyribonucleic acid）fingerprinting (also called DNA profiling or DNA typing) used for human identification in 1984 . Following the discovery of DNA fingerprinting, the United Kingdom was the first country to apply DNA evidence in criminal case in 1986. DNA fingerprinting was first introduced into the United States in a rape case in 1987. Taiwan used DNA fingerprinting to identify the bodies in a gun-fire case on April 1992. For more than one decade as forensic DNA used in Taiwanese criminal trials, this thesis aims through empirical study to illustrate that true picture.

The discovery of DNA fingerprinting was not only a great achievement in forensic science, but also became one of the most powerful investigative tools in forensics. Although DNA evidence revolutionized forensic science, its introduction into the courtroom was not without controversy. In light of the nature of DNA test, this may cause technical errors or population genetics errors. Thus, DNA evidence still meets some challenges in criminal trials.

The research in this thesis combines methods of literature review, content analysis, statistical analysis and questionnaire survey. First, the literature review was employed to discuss the development of DNA, techniques of DNA fingerprinting, forensic DNA and DNA evidence applied in the United States criminal trials. Second, the questionnaire survey was being administered to judges, public prosecutors and attorneys on jurisdictions of Taiwan Taipei, Banciao and Shihlin District Court. Third, four years case materials related DNA evidence were collected and analyzed by content analysis method. Finally, this thesis submits conclusions and suggestions according to statistical analysis.