The proof of criminal evidence is vast due to the tremendous scientific revolution in evidence which is unprecedented. It is based on precise scientific theories and origins and has provided the judge with conclusive and decisive evidence linking or denying the relationship between the accused person and the crime. They have convictions or exonerations when forensic evidence are as follows: it may be the confession of the accused or the testimony of witnesses, or mental evidence including such as presumptions, which are substantial evidence as called as the silent evidence. Hence, the importance of the substantial evidence by dealing with modern scientific means. The scientific evidence are based on scientific assets and facts that are not recognized in the past. They have begun to occupy their proper position in the field of criminal proof, in terms of their strength, stability, and confidence in their scientific sources. Hence, the importance of the judge's authority in assessing the scientific evidence because of its importance in modern criminal evidence. The judge's power to assess evidence does not fall within the framework of the three evidentiary systems: the system of legal evidence, the mixed evidence system, and the system of moral evidence as: "The judge must rule the case in accordance with the faith on which he has established his full freedom.