The Use of Probabilistic and Statistical Methods to Test the Significance of Scientific Evidence: Comparative Analysis of Current Forensic Practices in Russia and Abroad

Abstract

The article addresses the problem of developing scientifically sound approaches and quantitative criteria for assessing reliability of expert evidence that take into account the contextual information contained in case materials and are based on likelihood ratios. The evolution of the system of views on this problem in forensic science theory in Russia and abroad is considered, and the European Network of Forensic Science Institutes Guideline for Evaluative Reporting in Forensic Science is analyzed. The Guideline was published in 2015. This manual is a practical tool for experts assessing the evidentiary value of their conclusions resulting from specific types of forensic examination. It also sets out recommendations on how to present the results of such an assessment in the format of the so-called “evaluative report”. The starting point of the comparative analysis is the problem of how the legal system and its subjects interpret the results reported by an expert witness, as well as any other forensic evidence expressed in probabilistic terms. At present the probabilistic way of describing uncertainties, originating in the natural sciences, is firmly established in criminalistics and forensic science. A clear position that has formed in the context of the Russian legislation, theory and practice of forensic expertise is to interpret probability as synonymous with assumption. In the foreign forensic science community the fate of probabilities was different. The authors emphasize the practical value of further improving the tools for assessing the reliability of examination results in the forensic sciences and related areas.

Keywords

• судебная экспертиза
• оценка результатов экспертного исследования
• частотно-вероятностный метод
• отношение правдоподобия