Is to file a case and arrest people. According to the Procedural Provisions of Public Security Organs in Handling Criminal Cases: Article 187 A public security organ shall promptly investigate a criminal case that has been put on file, and comprehensively and objectively collect and obtain evidence of the criminal suspect's guilt or innocence, light crime or heavy crime. Article 188 After investigation, the public security organ shall conduct a preliminary examination of cases with evidence to prove the facts of the crime, and examine and verify the authenticity, legality and probative force of the evidence materials collected and collected. Article 189 When investigating a crime, a public security organ shall take compulsory measures and investigation measures in strict accordance with legal conditions and procedures. It is strictly forbidden to take coercive measures and investigation measures against criminal suspects only on suspicion without evidence.