The application of the rules of inquisitorial system, and the sensitivity of the pre-trial stage in gathering the evidence and the possibility of arbitrative decisions by the judicial authorities, demonstrate its importance in comparison with other proceedings. Therefore, this stage has received more attention in international human rights instruments. The High Disciplinary Court of Judges as a reference for investigating disciplinary offenses of judges has issued numerous decisions in favor of prosecuting judges violating defendants' rights and freedoms in the pre-trial stage. A review of the judges 'disciplinary procedure shows that this court has issued numerous and well-deserved verdicts guaranteeing some of the defendants' rights and freedoms in the pre-trial phase, but notwithstanding of Companionship this court with a human right court, in comparison with  human rights documents, its jurisprudence has not been able to comprehensively defend defendants' rights at this stage.

 The inequality of the powers of the prosecutor and the accused and the increasing powers of the court in ascertaining the truth are important features of the Inquisitorial system, and arbitration proceedings, the equality of powers of litigants and the passive role of the court in dealing with their reasons are features of the Adversarial system. Italy and Iran have taken steps to accept the components of Adversarial Model. The 1988 Criminal Procedure Code of Italy, inspired by the accusatory system, created fundamental reforms in the provisions of the 1930 Criminal Procedure Law, which are useful for Iranian legislators to study.

 This research was done using library sources in a descriptive-analytical way.Findings of the research: Some reforms of the Italian legislature were not successful in accepting the components of the prosecution in the judicial culture of this country and were sidelined by the opinions of the Constitutional Court. Iran's criminal procedure system has accepted manifestations of the accusatory system since the passage of removing the prosecutor's office in the Law on the Establishment of Public Courts and the Revolution of 1996 and the recognition of some defense rights in the Criminal Procedure Code of 2017. However, with the revival of the prosecutor's office headed by the prosecutor; Consolidation of powers to detect, prosecute and investigate crimes in the prosecutor's office; Delegating the authority to conduct preliminary investigations to the prosecutor in crimes other than Article 302 of the criminal procedure; the authority to supervise on investigator by prosecutor; Agreeing or disagreeing with the final orders and supply orders leading to the arrest of the accused; Superiority of the prosecutor's powers in relation to other litigants; The entry of judicial authorities into issues related to the separation of attorneys into approved and unapproved attorneys; The consolidation of executive and judicial powers of investigation and proceedings at the court stage and the possibility of issuing judgments without the presence of litigants has made the path of acceptance of accusatory proceedings in Iran uneven.

The relationships between the prosecution service and the police follow distinctive models (hierarchical or network) in accordance with the ruling procedure system (accusatorial or inquisitorial). In the system of the Islamic Republic of Iran, the hierarchical model is used in the relationship between the prosecution service and the police. Studies show that there are deficiencies in the relationship between the two organizations. The present article seeks to provide an optimal model of the relationship between the prosecution service and the police in the Islamic Republic of Iran. This research has used the library methodology, and the proposed model is designed according to the existing circumstances and realities of Iran's criminal justice system and addresses its aspects. The model of prosecution service and police relations at its best situation, results in more efficiency and effectiveness in detecting, prosecuting and investigating crimes. The aspects of the optimal model for Iran's police and prosecution service relations are as follows: 1- Assignment the crime detection function to the police, 2. Two-way communication based on the network model between the two police and prosecution service and, as a result, the equality of the two organizations with each other 3. Assignment of execution of investigations to the judicial police, 4. Separation of the investigating authority based on the severity of the crimes 5. The administration of the prosecution service on the judicial police; in this way, the judicial police are established and run under the dominion of the prosecution service, and at the same time, in proportion to the circumstances, enjoy a flexible and moderate sovereignty.