In the modern world we are confronted with newtechnological realities, and market knowledge, which become more complex by the globalization process. Moreover, undoubtedly scientific and technological advances open new prospects for the right. However, the law remains outside the epistemological approaches, particularly in the field of proof. The process itself is a process that requires knowledge of the testas a tool to verify and contrasting scenarios thatarise between the parties. The problem is that in a complex society can happen damaging facts with a high difficulty in identifyingthe perpetrators and accomplices. This raises the need to studythe criteria under test of knowledge, which will establish the truth concerning the process where it is determined or declared about the facts. There is no doubt that in the activity and evidential reasoning is indispensable the application of general rules of epistemology.