Background and Aim: Among the different stages of the criminal proceedings, the preliminary investigation stage is more important. The purpose of this article is to examine preliminary research models regarding the integration and separation of research from prosecution.
Materials and Methods: The research method is descriptive and analytical. The materials and data are also qualitative and data collection has been used
Ethical Considerations: In this article, the originality of the text, honesty and trustworthiness are respected.
Findings: In designing a suitable criminal procedure for every society, two points are important. First, a suitable criminal procedure is impossible except by thinking on the basis of models and modeling, and it is only with this method that different and conflicting pole are recognized and based on this knowledge. It is possible to use the best variables, and secondly, the design of the criminal procedure should be based on the social expectations of the society. It is a decades-old model that has entered the field of human sciences, and by having its own elements and components and emphasizing the different values of the path of the society's criminal procedure. determines
Conclusion: Modeling in the procedure is based on emphasizing the three elements of fair procedure, which are ethical principles, human rights and proper structure.