legal ground
Article 1 15 of the Criminal Procedure Law of People's Republic of China (PRC).
The public security organ shall investigate the criminal cases that have been put on file, and collect and obtain evidence of the criminal suspect's guilt or innocence, light crime or heavy crime. An active criminal or a major suspect may be detained in advance according to law, and a criminal suspect who meets the conditions for arrest shall be arrested according to law.
Article 162
When investigating a closed case, the public security organ shall ensure that the facts of the crime are clear and the evidence is true and sufficient, write a prosecution opinion and transfer it to the people's procuratorate at the same level for examination and decision together with the case file and evidence; At the same time, inform the criminal suspect and his defense lawyer about the transfer of the case. If a criminal suspect voluntarily pleads guilty, it shall be recorded and transferred with the case, and the relevant information shall be stated in the prosecution opinion.
Article 163
In the course of investigation, if it is found that the criminal suspect should not be investigated for criminal responsibility, the case shall be dismissed; A criminal suspect who has been arrested shall be released immediately, issued with a release certificate and notified to the people's procuratorate that originally approved the arrest.
skill
The above answer is only for the current information combined with my understanding of the law, please refer carefully!
If you still have questions about this issue, I suggest you sort out relevant information and communicate with professionals in detail.