Legal basis: Criminal Procedure Law of People's Republic of China (PRC).
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, and write a prosecution opinion, which shall be transferred 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.
163rd in the process of investigation, it is found that the criminal suspect should not be investigated for criminal responsibility, and the case should 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.
Article 175 When examining a case, the people's procuratorate may request the public security organ to provide evidence materials necessary for the trial; If he thinks that there may be cases of collecting evidence by illegal means as stipulated in Article 54 of this Law, he may be required to explain the legality of collecting evidence.