The material truth sought in law starts from the factual state and is expressed in the correspondence of the conception of facts with the actual state. This paper examines the search for material truth, that is, the determination of the factual situation in legal processes from an epistemic perspective. The epistemological responsibility of legal systems is to provide procedures that, when evaluating the evidence presented, lead to the objectively justified conviction that the truths about certain facts are true. However, the process of determining what is factually true may fail because it depends on the biases to which people are prone during testimony and decision-making, but also on the existing processes on which a legal system is based. This paper questions the sustainability of the veritistic feature in the legal process and hypothesizes that a correct judgment should be based on correct procedures of searching for material truth, and these procedures are correct to the extent that they promote correct judgments, that is, objectively reasonable beliefs that they are true concerning some facts when evaluating the presented evidence, really correct. Through the analysis of legal processes and the use of empirical examples and relevant research, the process of cognition and judgment of individuals and groups is observed when making decisions in legal proceedings, as well as a comparison of the determination of material truth in the continental and Anglo-Saxon legal systems. The scientific contribution of this work is to identify challenges in determining material truth, evaluating existing practices, and defining the influence of bias in the presentation of testimony, formation of beliefs, and decision-making, all to improve existing models in legal processes and create procedures for more reliable prediction of the behavior of the actors involved. The conclusion is that the epistemic responsibility of legal systems is unquestionable the legal education of all participants in the legal process is necessary, and that the promotion and acceptance of interdisciplinarity can be a corrective to existing legal practices and enable them to approach their epistemic goal.