1. Introduction

The Fourth Plenary Session of the 18th Central Committee of the Communist Party of China clearly proposed to "improve the system of leniency for guilty pleas and acceptance of punishment in criminal proceedings". Subsequently, 18 cities took the lead in launching pilot programs for the system of leniency for guilty pleas and acceptance of punishment in criminal cases. In 2018, the Criminal Procedure Law was revised to formally incorporate this system. In 2019, the Supreme People's Court, the Supreme People's Procuratorate, the Ministry of Public Security, the Ministry of State Security, and the Ministry of Justice jointly issued the Guiding Opinions on the Application of the System of Leniency for Guilty Pleas and Acceptance of Punishment (hereinafter referred to as the Guiding Opinions), marking the official launch of the reform of the system of leniency for guilty pleas and acceptance of punishment with Chinese characteristics [1]. After a series of interconnected development stages, this system has become a prominent topic of focus in China. Among existing works, discussions and debates mostly center on specific judicial practice links such as the procuratorial organ’s prosecution review and the court’s trial. This not only reflects the trial-centered reform trend of China’s criminal procedure system and the current situation where procuratorial organs have actively promoted the implementation of the system in recent years, but also facilitates comparative analysis with foreign systems mainly applied at the trial stage, such as plea bargaining in the United States and criminal procedure negotiation in Germany [2].

In the criminal proceedings process, the trial stage is the "core", the prosecution review stage is the "leading link", and the investigation stage is the "outpost". However, there is still significant academic controversy regarding whether the system of leniency for guilty pleas and acceptance of punishment should be applied at the investigation stage. Some scholars argue that the application of this system will lower the standard of proof [3], lead investigators to neglect evidence collection, over-rely on confessions from criminal suspects, and result in wrongful convictions [4]. On the other hand, some hold the view that applying the system at the investigation stage is conducive to improving the pretrial diversion mechanism for cases [5]. Against this backdrop, combined with the overall trend of judicial system reform, it is particularly urgent and important to conduct an in-depth empirical analysis of the actual operation of the system of leniency for guilty pleas and acceptance of punishment at the investigation stage.

This paper focuses on 3617 judicial documents selected between 2019 and 2024 to analyze the practical application of the system of leniency for guilty pleas and acceptance of punishment at the investigation stage. Through an in-depth evaluation of the system’s implementation effects, it further puts forward targeted improvement suggestions.

2. Empirical study on the application of the system of leniency for guilty pleas and acceptance of punishment at the investigation stage

This paper uses the Xiaobaogong Legal Empirical Analysis Platform as the data collation tool, with cases sourced from China Judgments Online. Four search criteria are regarded as "constant criteria": (1) Full-text search: guilty plea and acceptance of punishment at the investigation stage; (2) Case type: criminal cases; (3) Document type: judgments, rulings; (4) Timeframe: 2019–2024. Through careful manual screening of the search results, the author obtained a total of 3617 valid judicial documents regarding the application of the system of leniency for guilty pleas and acceptance of punishment at the investigation stage. Based on these data, the author further conducts an in-depth analysis of the current application status of the system at the investigation stage.

2.1. Regional analysis of cases

From the perspective of regional distribution, Zhejiang Province has the largest number of criminal cases applying the system of leniency for guilty pleas and acceptance of punishment at the investigation stage, with 3006 cases (see Table 1), accounting for 83.108% of the total sample (calculated to three decimal places and then rounded off, the same below). Heilongjiang Province ranks second with 229 cases, accounting for 6.331% of the total sample. The actual application of the system is strongly influenced by local judicial policies. In 2020, Zhejiang Province stipulated that if a criminal suspect pleads guilty and accepts punishment at the investigation stage, their base penalty term could be reduced by 30% [6]. In the same year, Heilongjiang Province stipulated that public security organs must inform criminal suspects of their litigation rights in accordance with the law during the first interrogation [7]. In 2022, the application rate of the system of leniency for guilty pleas and acceptance of punishment in Heilongjiang Province reached 92.3% [8]; in 2023, the number of people who applied for the procedure of leniency for guilty pleas and acceptance of punishment in Zhejiang Province reached 124,319 [9]. Judicial protection of human rights has been further strengthened, effectively reducing the degree of social confrontation and thus promoting a harmonious social atmosphere.

However, during the search in Beijing, Shanghai, and other provinces/municipalities, it was found that the number of cases involving guilty pleas and acceptance of punishment at the investigation stage is scarce. This may be attributed to differences in the standards for online disclosure of court judicial documents across regions. In fact, judicial organs in Beijing, Shanghai, and other regions also widely apply the system of leniency for guilty pleas and acceptance of punishment in criminal proceedings. As one of the first pilot regions for the system, Shanghai saw its application rate rise from 16% at the start of the pilot program in 2017 to 89.6% in 2023, and the appeal rate of cases involving guilty pleas and acceptance of punishment in the city was 1.9%, 15.5 percentage points lower than that of other criminal cases [10]. In Beijing, the application rate of the system increased from 64.8% in 2019 to 87.8% from January to July 2021, with an appeal rate of 4%, 5.9 percentage points lower than that of other criminal cases. From January to July 2021, a total of 117 criminal suspects who pleaded guilty and accepted punishment at the investigation stage were decided not to be prosecuted by procuratorial organs in accordance with the law. In addition, the proportion of cases where procuratorial organs recommended the application of the system of leniency for guilty pleas and acceptance of punishment at the investigation stage increased from 24.5% in 2019 to 42.9% in 2021 [11]. The regional analysis of cases shows that the system of leniency for guilty pleas and acceptance of punishment has made progress and been gradually implemented nationwide, but there are differences in the speed and implementation effect of its promotion [12].

2.2. Analysis of case offense types

As shown in Table 2, the most common type of case is Property Crimes, followed by Crimes against Public Security, and then Crimes of Obstructing the Administration of Public Order. These three types of cases together account for 90.185% of the total number of cases. However, the number of cases involving Crimes of Infringing upon Citizens’ Rights of the Person and Democratic Rights is only 208, accounting for 5.751%. Through the analysis of the types of offenses in the above cases, it can be seen that at the investigation stage, the policy of leniency for guilty pleas and acceptance of punishment is widely applied to traditional property crimes and new types of cybercrimes, but its application is relatively limited in crime types involving violations of personal rights. Combined with data analysis, among Property Crimes, there are 930 cases of theft and 327 cases of fraud; among Crimes against Public Security, there are 1054 cases of dangerous driving; among Crimes of Obstructing the Administration of Public Order, there are 68 cases of aiding activities of cybercrime. The total number of cases of these four offenses accounts for 65.773% of the total number of cases. The reason for this is that in most theft and fraud cases, since the defendants often return stolen property, make compensation, and obtain understanding from the victims or their affiliated units, lenient treatment can be considered if the defendants plead guilty and accept punishment and sign a written statement. Therefore, at the investigation stage, the application rate of guilty pleas and acceptance of punishment is relatively high for theft and fraud cases. In most cases of dangerous driving, the defendants are prosecuted for drunk driving. Due to the relatively short penalty terms and the low subjective maliciousness of the defendants, as long as the defendants voluntarily plead guilty and accept punishment, actively assist judicial organs in investigation and handling, and compensate for the losses caused by traffic accidents, the possibility of applying probation will be greatly increased. Therefore, the rate of guilty pleas and acceptance of punishment by defendants in dangerous driving cases is also relatively high. Among Crimes of Infringing upon Citizens’ Rights of the Person and Democratic Rights, there are 127 cases of intentional injury, accounting for 61.058%. Among these cases, 54 defendants obtained the victims’ understanding, 6 cases reached criminal reconciliation, and finally 52 cases applied probation. Through a comparative analysis of the specific judicial documents, it is concluded that in such cases, if the defendant pleads guilty and accepts punishment and there are other mitigating circumstances such as the victim’s understanding, the proportion of probation application in the final sentencing is relatively high. Among the 54 cases where the defendants obtained understanding, most of the victims suffered first-degree or second-degree minor injuries. There were 2 cases of serious injury and 1 case of death, in which the defendants were determined to have committed excessive self-defense. This fact reflects that judicial organs adopt a cautious attitude towards the application of leniency for guilty pleas and acceptance of punishment when handling intentional injury cases involving aggravating circumstances. Therefore, the lenient treatment of serious violent crimes and the specific extent of such leniency need to be carefully considered and judged based on the specific circumstances of each case.

2.3. Analysis of "procedural leniency"

2.3.1. Analysis of case application procedures

As shown in Figure 1, among the 3617 cases, 1779 cases were heard through the Fast-Track Sentencing Procedure, accounting for 49.184%; followed by 1362 cases through the Summary Procedure, accounting for 37.656%; the number of cases through the Ordinary Procedure was the smallest, with 476 cases accounting for 13.161%. It can be seen that in cases involving guilty pleas and acceptance of punishment at the investigation stage, the Summary Procedure and Fast-Track Sentencing Procedure are widely applied. The work of classifying cases by complexity and expediting the handling of simple cases has made significant progress, forming a mutually reinforcing effect with the system of leniency for guilty pleas and acceptance of punishment.

2.3.2. Application of compulsory measures at the investigation stage

As shown in Table 3, the judicial documents of cases involving guilty pleas and acceptance of punishment at the investigation stage from 2019 to 2024 show that 1615 people were released on bail pending trial, 3731 were placed under criminal detention, 74 were under residential surveillance, and 1203 were arrested. The most commonly used criminal compulsory measure by investigation organs is criminal detention, which is approximately 2.2 times the total number of people under residential surveillance and release on bail pending trial. This indicates that non-custodial compulsory measures for investigation and evidence collection have not been widely applied.

2.4. Analysis of "substantive leniency"

2.4.1. Sentencing comparison of cases at different stages

As shown in Figure 2, the probation application rate for cases involving guilty pleas and acceptance of punishment at the investigation stage is 24.855%, 82.361% of the defendants in the cases were sentenced to fixed-term imprisonment of less than 3 years, and 2.267% of the defendants were sentenced to fixed-term imprisonment of more than 10 years. This phenomenon indicates that the system of leniency for guilty pleas and acceptance of punishment has been widely applied in minor crime cases.

For comparative analysis, the first "constant criterion" was changed from "Full-text search: guilty plea and acceptance of punishment at the investigation stage" to "Judgment result: guilty plea and acceptance of punishment at the trial stage", and the data were collated and analyzed to obtain the following figure (see Figure 3). It can be seen that in cases involving guilty pleas and acceptance of punishment at the trial stage, the probation application rate is 23.789%, 91.336% of the defendants were sentenced to fixed-term imprisonment of less than 3 years, and 3.231% of the defendants were sentenced to fixed-term imprisonment of more than 10 years.

The "Full-text search: guilty plea and acceptance of punishment at the investigation stage" was changed to "Judgment result: guilty plea and acceptance of punishment at the prosecution review stage". Due to the large number of cases, the author conducted a partial sampling survey of the data and plotted the following figure (see Figure 4). It can be seen that in cases involving guilty pleas and acceptance of punishment at the prosecution review stage, the probation application rate is 27.287%, 95.455% of the defendants were sentenced to fixed-term imprisonment of less than 3 years, and 1.518% of the defendants were sentenced to fixed-term imprisonment of more than 10 years.

Comprehensive comparison of the above data shows that the proportion of defendants sentenced to fixed-term imprisonment of less than 3 years, from highest to lowest, is in the prosecution review stage, trial stage, and investigation stage; the probation application rates at the investigation stage and prosecution review stage are basically the same, which are lower than that at the trial stage; there is a large gap in the proportion of cases where defendants are sentenced to fixed-term imprisonment of more than 10 years, from highest to lowest, it is the trial stage, investigation stage, and prosecution review stage. According to the Guiding Opinions, the extent of leniency for guilty pleas and acceptance of punishment should be different at different stages. Specifically, the leniency extent for pleading guilty at the investigation stage, prosecution review stage, and trial stage shows a decreasing trend, and a hierarchical sentencing leniency mechanism should be applied [13]. However, according to the above empirical analysis, the sentencing difference of "pleading guilty early is better than pleading guilty late" is not significant.

2.4.2. Analysis of sentencing circumstances in cases at the investigation stage

As shown in Figure 5, in cases involving guilty pleas and acceptance of punishment at the investigation stage, the two statutory sentencing circumstances of confession and voluntary surrender dominate, and they are frequently applied in parallel with the system of leniency for guilty pleas and acceptance of punishment. This indicates that although the current law does not clearly define the specific relationship between them, in judicial practice, they are often applied simultaneously rather than as an alternative. For example, in the fraud case of Zhang Moumou, although Zhang Moumou was a recidivist in fraud cases, the court finally gave him a lenient punishment and sentenced him to 13 years and 11 months of fixed-term imprisonment in consideration of his confession and attitude of guilty plea and acceptance of punishment. In this case, even though the defendant committed a serious crime and faced a long sentence, it did not prevent the application of the system of leniency for guilty pleas and acceptance of punishment.

2.5. Analysis of defense situation

While keeping the "constant criteria" unchanged, keywords such as "entrusted defense", "appointed defense", and "defense counsel" were added one by one to the "full-text search" box, and duplicate values were removed to analyze the defense situation. Among the 3617 judicial documents involving 3771 defendants, 921 defendants received entrusted defense (see Table 4), accounting for 24.432%; 132 cases involved appointed defense, accounting for 3.501%, totaling 27.933%. It can be seen that the criminal defense rate in cases applying the system of leniency for guilty pleas and acceptance of punishment at the investigation stage is relatively low. From the perspective of system operation, in cases involving guilty pleas and acceptance of punishment, the remaining cases except those with entrusted defense and appointed defense are handled by duty lawyers, thereby achieving "full coverage of criminal defense" [14]. Therefore, the author conducted a specific analysis of the remaining judicial documents and found that compared with cases with defense counsel, only 7 judicial documents of cases without defense lawyers mentioned the relevant opinions of duty lawyers. In most cases, the role of duty lawyers is limited to "witnessing the signing of the Written Statement of Guilty Plea and Acceptance of Punishment". This means that the duty lawyer system has not played its due role well, and duty lawyers are becoming "witnesses".

3. Problems in the application of the system of leniency for guilty pleas and acceptance of punishment at the investigation stage

3.1. "High" pre-litigation detention rate

In judicial practice, China’s current criminal proceedings still rely on the pre-litigation detention approach, with the problem of a "high" pre-litigation detention rate [15]. Some scholars’ research shows that the confession rate of criminal suspects during the first interrogation at the investigation stage is over 70%, and can reach 90% by the end of the investigation [16]. However, at the same time, investigation organs have taken criminal detention measures against more than 93% of criminal suspects [17]. From this, it can be seen that China’s criminal proceedings still follow the principle of "taking custody as the norm and non-custody as the exception", and whether a criminal suspect pleads guilty is not an important factor considered during the review of arrest. The consequences of applying non-custodial compulsory measures, such as increased risks of controlling criminal suspects and higher case-handling costs for investigation organs, coupled with the influence of the traditional social concept of "detaining to await punishment", make judicial organs "proceed with extreme caution" when making non-custodial decisions. At the same time, the basic requirement of criminal justice is to focus on the overall situation of "maintaining stability". However, non-custodial measures may arouse psychological resentment among the victims, leading to continuous petitions and appeals, and may even trigger mass incidents, adding new unstable factors. In fact, non-custody is not opposite to crime control; the adoption of non-custodial measures is an important manifestation of protecting the human rights of criminal suspects and an inherent requirement for promoting the development of the system of guilty pleas and acceptance of punishment at the investigation stage.

3.2. "Unmanifested" hierarchical sentencing leniency

The Guiding Opinions clearly state that in terms of penalty evaluation, we should adhere to the principle that "pleading guilty early is better than pleading guilty late", uphold the principle of suiting punishment to crime and responsibility, and apply a hierarchical sentencing leniency mechanism. However, through the empirical analysis of judicial documents from 2019 to 2024, it can be seen that the current cases applying the system of leniency for guilty pleas and acceptance of punishment at the investigation stage are characterized by "unmanifested" hierarchical sentencing leniency [18]. This may be attributed to the lack of a unified and clear standard for the differences in sentencing leniency across the country. The newly promulgated Criminal Procedure Law does not specifically clarify how to give lenient treatment to acts of guilty pleas and acceptance of punishment at different litigation stages; the Measures on Leniency issued during the pilot stage of the system of leniency for guilty pleas and acceptance of punishment only states that guilty pleas and acceptance of punishment "may be given lenient treatment in accordance with the law", and also fails to clearly elaborate on the differentiated leniency standards for acts of guilty pleas and acceptance of punishment at various litigation stages. This has led to the phenomenon in judicial practice where lenient punishment is imposed uniformly on acts of guilty pleas and acceptance of punishment at different litigation stages [19].

3.3. Transformation of duty lawyers into "witnesses"

The duty lawyer system is committed to achieving full coverage of legal aid in criminal procedure procedures and can be called the last line of defense for legal aid. However, combined with the current practical situation and the empirical analysis conducted earlier, the problem of duty lawyers being transformed into "witnesses" is relatively prominent [20]. According to the revised Criminal Procedure Law in 2018 and the Guiding Opinions, duty lawyers mainly assume three functions: 1. Providing legal assistance; 2. Putting forward opinions on lenient punishment; 3. Witnessing the signing of the written statement of guilty plea and acceptance of punishment. From the perspective of legislative purpose, duty lawyers are in the position of "assistants" to form a stepwise lawyer assistance system of "defense lawyers – legal aid lawyers – duty lawyers". However, at present, in practice, the role of duty lawyers as "assistants" has been weakened, and they have increasingly become "witnesses". As can be seen from the empirical analysis earlier, duty lawyers have not helped defendants make procedural choices or apply for changes in compulsory measures, nor have they played their "assistance function" of providing legal assistance and putting forward opinions on lenient punishment. Instead, their "witness function" of witnessing the signing of the written statement of guilty plea and acceptance of punishment has become prominent. This stems from the inherent flaw in the positioning of duty lawyers: the Criminal Procedure Law clearly distinguishes between duty lawyers and defense lawyers, resulting in the secondary status of duty lawyers, which to a certain extent weakens the effect of their performance of duties. Secondly, the lack of functional guarantees for duty lawyers has also led to their transformation into "witnesses". There is an urgent need to further implement the litigation rights of duty lawyers. The Criminal Procedure Law does not clearly define the right to review case files, the right to meet with clients, and other issues of duty lawyers, making the provision of "soliciting opinions from duty lawyers" a mere formality [21].

4. Solutions to the problems in the application of the system of leniency for guilty pleas and acceptance of punishment at the investigation stage

4.1. Promoting the non-custodialization of cases involving guilty pleas and acceptance of punishment

4.1.1. Optimizing the quantitative evaluation system for social dangerousness

Although China’s Criminal Procedure Law and its relevant judicial interpretations have set several specific provisions on the conditions of social dangerousness, in practice, there is still a lack of clear evaluation criteria. This makes the evaluation of social dangerousness a challenge in the process of reviewing arrests and assessing the necessity of custody, and there is often a tendency toward subjectivity and formalization in the evaluation results in practice. Especially against the background of the reform of the system of leniency for guilty pleas and acceptance of punishment, due to the excessive subjectivity of social dangerousness evaluation, the incentive mechanism for guilty pleas and acceptance of punishment cannot be reasonably examined, and its positive effects are easily overshadowed. This further leads to deviations in the function of social dangerousness evaluation and induces the phenomenon of custody being used as a "bargaining chip". Therefore, statistical knowledge can be used to develop computer algorithms, and public security assessment tools and pretrial risk assessment tools can be created to optimize the quantitative evaluation system for social dangerousness and enhance the procedural legitimacy and guarantee of arrest and custody measures.

4.1.2. Increasing non-custodial alternative measures

A notable feature of China’s current framework of compulsory measures is the relative lack of non-custodial alternative measures. Summons for detention are mainly used to ensure that the accused appears for interrogation, while detention is mainly targeted at active offenders and major suspects in emergency situations. Release on bail pending trial has limited practical binding force; residential surveillance is difficult to implement. The lack of non-custodial alternative measures puts public security and judicial organs in a dilemma when choosing compulsory measures at the pretrial stage: the existing non-custodial measures are difficult to ensure the smooth progress of criminal proceedings, while custody measures, although effective in controlling the accused, are too harsh. After weighing various factors, public security and judicial organs tend to choose the latter, which has become an important cause of the high pre-litigation detention rate in China’s judicial practice. In the future, on the basis of optimizing existing non-custodial alternative measures, we should also actively absorb foreign experience and develop more types of non-custodial alternative measures with varying degrees of severity, such as regular reporting of whereabouts and mandatory medical assessment and treatment. At the same time, we should promote the right-based reform of non-custodial alternative measures, that is, outside of statutory circumstances, the accused shall have the right to apply to judicial organs for non-custodial alternative measures to avoid unnecessary custody.

4.2. Establishing a stepwise sentencing leniency mechanism

4.2.1. Establishing hierarchical leniency standards

We should establish hierarchical leniency standards, formulate and issue relevant norms, and implement a gradually decreasing sentencing leniency standard of 30%, 20%, and 10% for the accused at the investigation, prosecution, and trial stages respectively. At the investigation stage, investigation organs have the responsibility to fully explain the guilty plea and acceptance of punishment to criminal suspects, ensuring that they voluntarily and proactively confess to crimes to the investigation organs and maintain consistency in their confessions in subsequent trials after fully understanding the possible penalty reduction effects of choosing this system. In such cases, they can enjoy a maximum of 30% reduction in sentencing. If the accused pleads guilty and accepts punishment at the prosecution review stage, the upper limit of sentencing reduction they can obtain is 20%. If the accused does not plead guilty and accept punishment until the trial stage, the maximum limit of sentencing reduction shall be 10%.

4.2.2. Utilizing the intelligent sentencing assistance system

At present, the use of the intelligent sentencing assistance system has become an important auxiliary means to improve the quality of sentencing recommendations and enhance judicial efficiency. We should continue to deepen the construction of smart procuratorial work, focus on building an intelligent interactive sharing platform for procuratorates and courts to share sentencing big data, and help improve the accuracy of sentencing recommendations and judicial efficiency. Of course, cases involving guilty pleas and acceptance of punishment vary in practice, so the intelligent sentencing assistance system can only play an auxiliary role. Prosecutors still need to exert their subjective initiative, and on the basis of referring to the sentencing results of the intelligent sentencing assistance system, comprehensively grasp the facts and circumstances of the case, and then put forward practical and accurate sentencing recommendations.

4.3. Giving full play to the role of duty lawyers

4.3.1. Transforming from "legal assistants" to "substantive defenders"

To achieve this goal, it is necessary to eliminate systematic obstacles and promote the transition of temporary duty lawyers to defense lawyers, establishing a stable entrustment relationship with criminal suspects. To this end, two paths must be unobstructed: First, establish a mechanism for duty lawyers to be transformed into entrusted lawyers. The current regulations prohibit duty lawyers from establishing economic interest relationships with criminal suspects, which has inadvertently made it difficult for lawyers who are most familiar with the case or most trusted by the criminal suspects to play a role throughout the litigation process. Therefore, this measure will help criminal suspects with financial conditions to better protect their rights and improve the quality of defense; Second, establish a system for duty lawyers to be transformed into assigned legal aid lawyers. Although duty lawyers and assigned legal aid lawyers both belong to the legal aid system, there is often a lack of effective communication between them, and they work independently. The establishment of this system aims to promote cooperation between the two parties and jointly advance the realization of the goal of "full coverage of criminal defense". Through the effective operation of the above two transformation mechanisms, duty lawyers can continuously provide defense throughout the judicial process of criminal suspects, truly becoming "substantive defenders".

4.3.2. Guaranteeing the litigation rights of duty lawyers

To guarantee the functions of duty lawyers, it is necessary to implement their litigation rights, with the core being to guarantee their right to review case files and right to meet with clients. First, to ensure the timeliness of meetings, additional provisions can be added to clearly stipulate that at the investigation stage, prior approval is only required for meetings with criminal suspects involved in state security and terrorist crimes; in other cases, investigation organs shall immediately arrange meetings after duty lawyers complete the formalities, ensuring that meetings are realized within 48 hours. Second, endow duty lawyers with comprehensive rights to review case files, including reviewing, extracting, and copying case files, and at the same time require case management departments to actively assist duty lawyers in completing case file review in practice. In addition, pilot projects for online case file review by duty lawyers can be explored, and the existing "online appointment and offline case file review" model can be gradually reformed, allowing duty lawyers to submit applications through the online system and directly review case materials online using electronic case file terminals.

5. Conclusion

Since 2019, the consistently high application rate of the system of leniency for guilty pleas and acceptance of punishment has laid a solid foundation for the deepening of theoretical research and the progress of practical operations, indicating that the opportunity to launch the stage of deepening the reform of the system of leniency for guilty pleas and acceptance of punishment is ripe. In investigation practice, great attention should be paid to the risks associated with applying the system of guilty pleas and acceptance of punishment to criminal suspects, reducing potential violations of the substantive rights of criminal suspects, and fully protecting the fundamental rights of criminal suspects, thereby safeguarding judicial fairness and authority. Therefore, it is necessary to accelerate the establishment of systems related to guilty pleas and acceptance of punishment at the investigation stage, realize the effective restriction and supervision of the exercise of public power, and improve the level of law-based application of the system of leniency for guilty pleas and acceptance of punishment at the investigation stage.