legal ground
Article 167th of the Criminal Procedure Law
If the people's procuratorate deems it necessary to arrest the detained person in a case directly accepted, it shall make a decision within 14 days. Under special circumstances, the time for deciding to arrest may be extended by one to three days. If there is no need for arrest, it shall be released immediately; If it is necessary to continue the investigation and meet the conditions for obtaining a guarantor pending trial or residential surveillance, the guarantor pending trial or residential surveillance shall be lifted according to law.