Collecting evidence is the activity of public security judicial staff to investigate, discover, obtain and save all information and materials related to the case in order to find out the truth of the case in accordance with legal procedures. Investigators, prosecutors and judges must collect all kinds of evidence that can prove the guilt or innocence of criminal suspects and defendants and the seriousness of the crime in accordance with legal procedures. It is strictly forbidden to extort confessions by torture and collect evidence by threats, enticements, deception or other illegal methods. It is necessary to ensure that all citizens who are related to or know the case have the conditions to produce evidence objectively and fully, and they can be hired to assist in the investigation except in special circumstances.
Collecting evidence has the following basic requirements: first, it must be carried out in strict accordance with legal procedures;
Second, take the initiative and be timely;
Third, it must be objective and comprehensive;
Fourth, pay attention to relying on the masses and using scientific and technological means;
Fifth, the collected evidence must be properly preserved.
Anyone who knows the case has the obligation to testify. A person who is physically and mentally defective or young, can't distinguish right from wrong and can't express correctly can't be a witness. Public security and judicial organs shall ensure the safety of witnesses and their close relatives.