1. Whether it is illegal evidence and whether it should be excluded needs to be judged based on the actual situation. The public security organ is required to issue proof that the source of the evidence is legal. The public security organ shall prove that the evidence was collected by no less than two people and obtained in a certified manner. If the holder cannot be proved or the evidence was collected in front of the holder, a witness shall be present. If the legality of the collection of evidence cannot be proven, it should be excluded. 2. As a criminal offense, proving guilt cannot rely on just one piece of evidence, but requires multiple pieces of evidence, and the evidence should be mutually corroborated to serve as the basis for finalizing the case. Lawyers need to consider the entire case and formulate a defense strategy. When other evidence has fully confirmed the facts of the crime, it is not conducive to the defense of innocence. Article 67 of the Procedural Regulations of the Public Security Organs in Handling Criminal Cases (Ministry of Public Security Order No. 127) If the collection of physical evidence or documentary evidence in violation of legal procedures may seriously affect judicial fairness, corrections or reasonable explanations must be made; corrections or reasonable explanations cannot be made , the evidence shall be excluded. Article 224 The number of investigators who shall seal up or detain shall not be less than two, and shall present the relevant certificates required by these regulations. Article 223 stipulates relevant legal documents. A record of seizure or seizure shall be made and signed by the investigators, holder and witnesses. If the identity of the holder is unknown or refuses to sign, the investigators shall indicate this in the transcript. Article 225: The property and documents seized or seized shall be clearly counted together with the witnesses present and the holders of the property and documents seized or seized, and a seizure or seizure list shall be made on the spot in triplicate, specifying the property. Or the name, quantity, characteristics and origin of the document, etc., shall be signed by the investigators, the holder and the witness, one copy shall be handed over to the holder, one copy shall be handed over to the custodian of the public security organ, and one copy shall be attached to the file for future reference. One copy is attached for reference. If the owner cannot be identified, or if the owner refuses to sign the property or document, investigators should note this on the list. Cultural relics, gold, silver, jewelry, calligraphy and paintings and other valuable property seized in accordance with the law shall be photographed or videotaped, and promptly appraised and valued.