The paper is divided into three larger parts. In the introductory part the author reminds us that the application of mathematics to assess the evidence is not a substantially new idea. Inquisition procedures prescribed the legal assessment of evidence that consisted of primitive mechanical adding and subtracting the available evidence. However, modern mathematical methods that can be used for assessing evidence are far more sophisticated, and are based on probability analysis and computer technology. In the second part the paper deals with some possibilities of applying the probability analysis to evaluate evidence. It particularly tackles the potential of the Bayes' theorem of conditional probability in evidence assessment. The third part is the conclusion in which the author emphasizes that scientific progress is extremely fast and that mathematics will enter even more into courtrooms and thus progressively increase the exact elements of the now primarily subjective process of evidence evaluation. It particularly emphasizes the advantages of Bayesian analysis, but it warns that the results of this method are only one' mathematical truth', and that interpretation is the key.