Article 7 of China's Criminal Procedure Law stipulates: "In criminal proceedings, the people's courts, people's procuratorates and public security organs shall be responsible for the division of labor, cooperate with each other and restrict each other to ensure accurate and effective law enforcement." Its basic spirit is that in criminal proceedings, the public, procuratorial and legal organs and their personnel can only coordinate according to this principle and handle the relationship among them well, so as to ensure the accurate and effective implementation of the law and jointly complete the criminal proceedings. Therefore, the principle of division of responsibilities, mutual cooperation and mutual restraint is the criterion for adjusting the relationship between the three powers in China, and it is also the basic scheme for the allocation of the three powers in China. This is not only a summary of the experience of criminal justice since the founding of the People's Republic of China, but also a reflection of China's current social situation and current criminal justice policies. It is true that this principle has played an active role in criminal proceedings in China. However, the problems exposed in practice, such as poor litigation relations and poor investigation mechanism, make us have to question whether this principle of criminal procedure with China characteristics has legal rationality. This paper attempts to reflect on this principle of criminal procedure from the understanding of the division of responsibilities, mutual cooperation and mutual restriction between public security and procuratorial organs and the current relationship between prosecutors and police in China.

Two, the public security and procuratorial organs are responsible for the division of labor, mutual cooperation and mutual restraint.

(1) Division of responsibilities. It means that the public security organs and people's procuratorates should have a clear division of labor in criminal proceedings, exercise their functions and powers within the scope of functions and powers prescribed by law, and perform their duties, which can neither replace each other nor shirk each other. The essence of the division of responsibilities is to allocate the power of the state to investigate crimes to different organs. Its purpose is to disperse power to different state organs through the separation of rights, and to prevent excessive concentration of judicial power, thus resulting in arbitrariness and arbitrariness of judicial power. According to the relevant provisions of China's Criminal Procedure Law, the division of responsibilities between public security and procuratorial organs is reflected in criminal proceedings: (1) Division of litigation functions, that is, public security and procuratorial organs undertake different litigation functions respectively. Specifically, the public security organs are responsible for the investigation, detention, execution and pre-trial of criminal cases; Procuratorial organs undertake the functions of prosecuting criminal cases, approving arrests, directly accepting cases for investigation, initiating public prosecutions and protesting. (2) the division of functions and jurisdiction, that is, the division of authority of public security and procuratorial organs to directly accept criminal cases. Specifically, the procuratorial organs are responsible for filing and investigating crimes of corruption and bribery, dereliction of duty, illegal detention, extorting confessions by torture, retaliation and framing, illegal search and other crimes that violate citizens' personal rights and democratic rights. Upon the decision of the procuratorial organ at or above the provincial level, the functionaries of state organs may use their powers to implement other major criminal cases, and may also file a case for investigation; The public security organs are responsible for filing and investigating all criminal cases except private prosecution cases filed by procuratorial organs and accepted by courts.

(2) cooperate with each other. The so-called mutual cooperation means that the public security and procuratorial organs should support, coordinate and cooperate with each other on the basis of division of responsibilities, complete the investigation and punishment of crimes, and protect innocent people from illegal investigation. Therefore, the division of responsibilities mentioned above does not mean that the public security and procuratorial organs go their own ways and divide the land into prisons. The purpose of establishing public security and procuratorial organs by the state is to investigate and deal with crimes, safeguard social public interests and safeguard citizens' legitimate rights and interests. The ultimate goal of public security and procuratorial organs is the same. It is based on this consistency that although the public security and procuratorial organs perform their respective duties in criminal proceedings, they must also closely cooperate and coordinate with each other. The concrete manifestations of mutual cooperation between public security and procuratorial organs in criminal proceedings are as follows: (1) The public security organs should make preparations for the procuratorial organs to examine and approve the arrest and prosecution; (2) If the public security organ requests approval and meets the conditions for arrest, the procuratorial organ shall promptly approve the arrest; If it is necessary to detain or arrest a criminal suspect in a case put on file for investigation by a procuratorial organ, it shall be decided by the procuratorial organ and executed by the public security organ; (3) When the procuratorial organ needs a wanted criminal suspect, it shall notify the public security organ to execute it.

(3) contain each other. The so-called mutual restraint means that the public security organs and procuratorial organs restrict and balance each other according to the division of responsibilities in criminal proceedings, so that problems, shortcomings and mistakes in their work can be found and corrected in time, and the correct implementation of the law can be ensured, so that nothing is missed or wasted. Decentralization and checks and balances are common power restriction mechanisms in modern society. Decentralization and checks and balances are inseparable. Decentralization is the premise and checks and balances are the foundation. Without the separation of powers, it is impossible to prevent excessive concentration of power. Only decentralization, without mutual checks and balances between powers, is still not enough to prevent arbitrary power. Therefore, on the basis of decentralization, there must be mutual checks and balances between powers, and criminal judicial power is no exception. The mutual restriction between the public security and the procuratorial organs is reflected in the criminal proceedings: (1) The procuratorial organs are the legal supervision organs of the country, which supervise the criminal proceedings according to law, and of course supervise the investigation activities of the public security organs. Specifically, they supervise the legality of the investigation activities of the public security organs by means of filing supervision, examining and approving arrests, examining and prosecuting, and accepting complaints. In this sense, procuratorial organs restrict public security organs. (2) At the same time, the public security organs also restrict the procuratorial organs. If the public security organ thinks that the decision of the procuratorial organ not to approve the arrest is wrong, it may request reconsideration; if it does not adopt the opinion, it may also submit it to the procuratorial organ at the next higher level for review; If the public security organ thinks that the decision of the procuratorial organ not to prosecute is wrong, it may request reconsideration, and if the opinion is not adopted, it may also submit it to the procuratorial organ at the next higher level for review.

Three, the public security and procuratorial organs are responsible for the division of labor, mutual cooperation and mutual restraint.

(a), the public security and procuratorial organs are responsible for the division of labor, mutual cooperation, mutual restraint of legal doubt never principle. It should be admitted that the original intention of the public security and procuratorial organs to be responsible for the division of labor, cooperate with each other and restrict each other is understandable, that is, to correctly coordinate and handle the relationship between the two organs according to this principle to ensure the effective implementation of the law. But the rationality of reality does not necessarily have the rationality of jurisprudence. As mentioned above, in criminal proceedings, the actions of public security and procuratorial organs are consistent in the ultimate goal. It is this consistency that makes the investigation function of public security organs and the appeal function of procuratorial organs homogeneous. The investigation activities of public security organs are not independent, and the ultimate goal of investigation is to serve the accusation. The purpose of public security organs to find out criminal facts and collect evidence is to effectively support the appeal in court, and their investigation activities are essentially the function of appeal [1]. The common practice abroad is to take investigation as part of the appeal function. Modern criminal procedure mode advocates the tripartite structure of prosecution, defense and trial. Therefore, when positioning the relationship between investigation and prosecution, there is no doubt that the prosecution function should be placed in a dominant position, and the investigation function is only an auxiliary function of the prosecution function. Therefore, the relationship between investigation and prosecution, that is, the relationship between public security and prosecution, should be a master-slave relationship in essence. Based on this relationship, the procuratorial organ exercising the appeal function can of course supervise and restrict the public security organ exercising the investigation function. If the public security organ exercising investigation function can also restrict the procuratorial organ exercising appeal function in turn, it is the dislocation of litigation relationship. . Because the purpose of criminal proceedings should be to accurately and timely find out the facts of crimes, punish crimes and protect people, the public security organs are separated from judicial activities, but the public security organs responsible for collecting and fixing evidence do not directly bear the risk of losing the case due to insufficient evidence. This imbalance between power and responsibility will inevitably lead to the lack of sufficient internal motivation for investigators to collect and fix evidence in a timely and comprehensive manner. The procuratorial organ responsible for complaints is restricted by the public security organs and cannot ensure that the investigation meets the requirements of public prosecution. On the other hand, the division of responsibilities, mutual cooperation and mutual restraint are more reflected in an equal restrictive relationship, but at the same time, both the Constitution and the Criminal Procedure Law of our country stipulate that the procuratorial organ is the legal supervision organ of our country. When procuratorial organs appear as national legal supervisors, the relationship between procuratorial organs and public security organs is also reflected as a relationship between supervision and supervision. How to exercise supervision between equal subjects in criminal proceedings? This is also not feasible in jurisprudence.

(2) The relationship between prosecutors and police in China is based on the principle of division of responsibilities, mutual cooperation and mutual restraint. Under the principle of division of responsibilities, mutual cooperation and mutual restraint, the relationship between public security and procuratorial organs or between prosecutors and police in China has the following characteristics: (1) Separation of prosecutors and police. In other words, public security and procuratorial organs have equal status in criminal proceedings, and they are both subjects of criminal proceedings. Their power in criminal proceedings is responsible for division of labor, mutual cooperation and mutual restriction. There is no relationship between who obeys who and who leads who, and they belong to two different organs. (2) Police inspection and restriction. On the one hand, this restriction is reflected in the fact that the procuratorial organ is the legal supervision organ of our country, and it is of course within the scope of its functions and powers to supervise the legality of the investigation activities of public security organs. On the other hand, the public security organs also restrict the procuratorial organs, the most prominent performance of which is the right of reconsideration and review of the decision of the procuratorial organs not to arrest or prosecute. In other words, the restrictions on police inspection in China are two-way restrictions. This configuration actually emphasizes the independence and equality of the investigation function relative to the accusation function. Emphasizing this independence and equality will obliterate the dominant position of the appeal function and violate the distribution law of the investigation appeal function. Some problems exposed in judicial practice also show that there is a mechanism conflict in the current relationship between prosecutors and police in China. Such as (1) low litigation efficiency. The consistency between public security and procuratorial organs in the purpose of criminal proceedings requires that public security organs and procuratorial organs cooperate with each other to form a joint force of accusation and effectively accuse crimes. However, the independence, equality and two-way restriction between public security organs and procuratorial organs in criminal proceedings in China makes it difficult for procuratorial organs to restrict public security organs, and public security organs often go their own way, making their investigation activities unable to fully meet the appeal requirements, making the number of times for procuratorial organs to return to public security organs for supplementary investigation and self-supplementary investigation increase, thus reducing the efficiency of litigation. At the same time, the independence, equality and two-way restriction of public security and procuratorial organs often lead to wrangling and competition between public security organs and procuratorial organs, which not only reduces the efficiency of litigation, but also leads to the internal friction of accusation rights. (2) Due to historical and practical reasons, the two-way restrictive relationship between public security and procuratorial organs in China leads to the fact that public security organs are far larger than procuratorial organs, and it is difficult for procuratorial organs to effectively supervise the huge public security organs. At the same time, because the procuratorial organ is basically post supervision, there are still a lot of procedural violations when the public security organs exercise their investigation power.

Fourthly, the reconstruction of the relationship between prosecutors and police in China.

(1) academic point of view. Reforming the relationship between prosecutors and police is the most discussed topic in recent years. Among them, the most representative view is the theory of "the integration of prosecutors and police". The core of this theory is that procuratorial organs have the right to direct the criminal investigation activities of public security organs in criminal proceedings, thus improving and solving the problems such as "waste of judicial resources, low litigation efficiency and serious out-of-control investigation procedures" [2]. In this theory, some scholars believe that "the integration of prosecutors and police" should be the relationship of restriction, guidance and command between procuratorial organs and public security organs. Prosecutors have the leading power over criminal police's investigation activities, in fact, it is the command and control power, and criminal police are in a dominant position [3]; Another scholar suggested that the administrative and judicial functions of public security organs should be separated, and criminal police should be separated from public security organs. According to the principle of the integration of procuratorial organs and police, it should be controlled by procuratorial organs, that is, the integration of procuratorial organs and police not only refers to the restriction, guidance and command of business, but also has the relationship of organizational subordination, and the police organs are only regarded as auxiliary organs of procuratorial organs and have no substantive right to handle cases; Some scholars compromise and adjust the relationship between public security and procuratorial organs by imitating the smuggling crime investigation bureau, that is, put criminal police under the dual leadership of procuratorial organs and public security organs.

(2) On the reconstruction of the relationship between prosecutors and police in China. Improving the relationship between prosecutors and police can not be divorced from the reality and judicial tradition of China, completely copying foreign models, and must respect the development law of criminal proceedings. The theoretical basis of "the integration of prosecutors and police" is the separation of powers, which is divorced from the national conditions in China and the reality of the procuratorial system in China. If this concept is adopted, the legal supervision power and public prosecution power of procuratorial organs will be damaged, and at the same time, this concept also violates the development trend of modern legal system seeking more perfect restriction and balance. To reconstruct the relationship between prosecutors and police in China, we must pay attention to the following points: (1) Strengthen the legal supervision function of procuratorial organs. Legal supervision is the basic function entrusted to procuratorial organs by the Constitution. Only by strengthening legal supervision can we ensure the effective implementation of the law and the smooth completion of criminal proceedings and effectively safeguard fairness and justice. (2) Strengthen the awareness of evidence, and give the procuratorial organs the power to guide the public security organs to collect evidence. Public security organs are connected with judicial activities. Although they have the right to investigate and assume the responsibility of collecting and fixing evidence, they do not directly bear the risk of losing the case due to insufficient evidence. Procuratorial organs guide public security organs to obtain evidence from the perspective of conforming to the trial, so as to ensure that the investigation meets the requirements of public prosecution, improve the efficiency of litigation and ensure the quality of cases. (3) Give the procuratorial organs judicial authorization to appropriately limit the investigation behavior of public security organs and strengthen investigation control. Due to the lack of neutral judges in the investigation procedure in China, the activities carried out by the public security organs are all examined and authorized, which makes almost all the investigation measures and means decided by the public security organs themselves. To a great extent, this has led to the abuse of power by public security organs and even arbitrary infringement on criminal suspects. Give the procuratorial organs judicial authorization and strengthen external investigation control. Only in an emergency, the public security organ can conduct investigation first, but it must also be examined by the procuratorial organ afterwards. (4) Strengthen the procuratorial organs' right to supervise the filing of cases. The public security organ shall report to the procuratorial organ after filing the case; If it is revoked after the public security organ files a case, or if the procuratorial organ notifies the public security organ to file a case, it shall be approved by the procuratorial organ.