Although the methods and means of crime have evolved in the development of the societies in which its occurred, the crime is the same whether it occurred in the past, present or future. However, the way it is occurred now is more organized and may become more organized in the future. Considering the development of the methods and means of committing crimes, access to the accused became difficult. the reason of this is the lack of scientific tools to keep pace with the means used by the perpetrators, and therefore the society must use the same weapon used by the perpetrator which is the weapon of science and the development of modern scientific means aimed at detecting crimes and facilitate Prove it. Scientific evidence is a means of finding the link between crime and its perpetrator. It is one of the most important elements of criminal evidence, and the rate of mistake is very small and virtually non-existent. Therefore, DNA is one of the most important modern scientific methods that have been used by criminal justice bodies in different countries for the purpose of detecting both crime and criminal. Despite the importance of DNA as a means of modern scientific evidence aimed at criminal justice officials to reach the truth accurately, but it is still a controversial jurisprudence centered on the credibility and legitimacy of using it in the criminal evidence. In addition to its authentic in the composition of the conviction of the criminal judge. The question is if the DNA become a means to rely on Whether or not the criminal judge is convinced, although some legislation has adopted the DNA as evidence in criminal law. Therefore, we have decided to examine the issue of DNA and its authentic in the criminal evidence because of its great importance in our time and the absence of most of the legislation to be dealt with in the field of criminal evidence. We will examine it in four sections, first devoted to determine the nature of the DNA, while the second will discuss the characteristics and defects of the genetic fingerprint, And the third section deals with the areas and controls of the work of DNA, and finally we will examine the legitimacy of the DNA in the fourth and last.