According to Article 42 of China's Criminal Procedure Law: "All facts that prove the true situation of a case are evidence." Evidence in criminal proceedings has three basic attributes: one is objectivity. Any criminal act is committed at a certain time, place and under certain conditions. In the process of committing a crime, a person will always come into contact with things around him, and will inevitably leave some traces and objects reflecting criminal activities, or be heard and witnessed by victims and witnesses. These are objective beings that are independent of human will. Whether the judicial personnel realize it or not, they always exist. On the contrary, if it is not an objective fact, it is something subjective or illusory, such as conjecture, illusion, dreaming, superstition and so on. , can't be used as evidence.
The second is relevance. The objective facts as evidence must have some connection with the facts of the case, so that we can know the real situation of a certain part or aspect of the case. Objective things that have nothing to do with the facts of the case cannot reflect the nature or plot of the case or explain any problems in the case, so they cannot be used as evidence.
The third is legitimacy. Criminal evidence can only be collected by investigators, prosecutors and judges according to legal procedures, or provided by defense lawyers and private prosecutors according to law. The law prohibits judicial personnel from extorting confessions from criminal suspects and defendants by torture; Use violence to force witnesses to testify; Collect evidence by threats, seduction, deception and other illegal methods. All the so-called proof materials obtained by illegal means cannot be used as evidence in criminal proceedings, especially as a basis for finalizing a case. Only when judicial personnel collect, examine and use evidence according to legal procedures can they have legal effect.