According to the relevant laws and regulations, when several appraisers appraise the same person or the same article, each appraiser shall conduct it separately. When necessary, witnesses may be present.

Article 167 of the Rules of Criminal Procedure of the People's Procuratorate stipulates:

Two witnesses unrelated to the case shall be present at the inquest, and the transcripts of the inquest shall be signed or sealed by the participants and witnesses. The necessity and number of witnesses are limited. Moreover, this is only a procedural provision for procuratorial organs to handle self-investigation cases such as corruption and bribery.

The Ministry of public security "rules for on-site investigation of criminal cases by public security organs" stipulates in item 3 of Article 4:

On-site investigation must invite two impartial citizens who have nothing to do with the case as witnesses, and public security and judicial personnel cannot be witnesses. "

Paragraph 2 of Article 8 provides that:

"The record of on-site investigation shall be recorded in detail: the name, occupation and address of the witness; Signatures of on-site commanders, surveyors, record producers and witnesses ". This provision is more detailed, but the scope involved is limited to on-site inspection of witnesses.

Witnesses and the evidence they provide have the same legal effect. The difference is that the witness is decided by the case itself, and its task is to prove the facts of the case; Witnesses can choose, and their task is to observe and supervise whether the judicial personnel's activities such as inquest, inspection, search and seizure are correct and legal, so that legal litigation can be objectively recognized and have legal effect. If the parties have any objection to the correctness and legality of the above-mentioned acts, the witness shall testify about what he saw with his own eyes.