According to the second paragraph of Article 35 of the Lawyers Law, "if a lawyer investigates and collects evidence by himself, he can investigate the situation related to undertaking legal affairs with the lawyer's practice certificate and the certificate of the law firm", and the lawyer can directly investigate and collect evidence.
However, in criminal proceedings, the criminal procedure law has some restrictions on lawyers' investigation and evidence collection. According to the second paragraph of Article 41 of the Criminal Procedure Law, "with the permission of the people's procuratorate or the people's court, and with the consent of the victim or his close relatives or witnesses provided by the victim, the defense lawyer may collect materials related to this case." Only with the permission of the procuratorate or the court and the consent of the victim can a lawyer investigate and collect evidence from the victim.