What does it mean to send a text message to conduct an investigation?

Sending text messages to carry out investigation is in the process of criminal investigation. Investigation means that the case is in the process of criminal investigation, and the criminal identity and facts of the suspect cannot be confirmed before the investigation work of the public security organ is completed. However, before the criminal suspect is formally arrested, the procedural law and criminal law have not clearly stipulated the specific time limit for the public security organ to investigate the criminal case.