형사재판에서 과학적 증거 심사의 이론과 실제 - 최근의 미국 연방지방법원 판례 분석을 중심으로

Theory and Practice of Examining Scientific Evidence in Criminal Trials : Focusing on an Analysis of Recent U.S. Federal District Court Cases

This study conducts an in-depth examination of how scientific evidence is actually scrutinized in criminal trials through an analysis of recent rulings by U.S. federal district courts. The analysis reveals that U.S. courts evaluate the reliability of scientific evidence in a manner that is both rigorous and flexible, based on the Daubert standard and Federal Rule of Evidence 702. In particular, for traditional forensic fields such as fingerprint and firearms analysis, courts tended to acknowledge high reliability, grounding their decisions on long-accumulated validation studies and the establishment of standard procedures. Conversely, regarding new technologies such as Low Copy Number (LCN) DNA or complex DNA mixture analysis, it was evident that courts adopt a differentiated approach based on the maturity of the technology, by more closely scrutinizing the development and validation processes and compliance with standards. Most notably, the courts clearly distinguish between admissibility and weight in their approach. Unless there are fundamental flaws in the methodology itself, the general trend is to address issues of application errors or subjective interpretation in individual cases during the assessment of weight—typically through cross-examination—rather than excluding the evidence's admissibility. This can be interpreted as a reliance on the function of courtroom argumentation to discover the substantive truth within the structure of the adversarial system. Furthermore, it is impressive that courts provide guidelines on specific methods of testimony, such as strictly restricting definitive expressions like ‘100% certainty’ or ‘absolute exclusion,’ out of concern for the potential undue influence scientific evidence may have on jurors. Additionally, the flexible interpretation of the ‘general acceptance’ requirement—looking not at a simple majority but at practical usage by core expert groups or accreditation by authoritative institutions—can be evaluated as a pragmatic attitude attuned to the pace of scientific and technological advancement. These practices of U.S. courts provide significant implications for Korean criminal trials, where the importance of scientific evidence is increasingly growing.