Legal analysis: lawyers' investigation and evidence collection is conducive to the balance of prosecution and defense functions. In modern criminal proceedings, lawyers participate in litigation mainly to ensure the balance of litigation status between the prosecution and the defense. Lawyers stand on the defendant's side and show their strength against prosecutors in court. The evidence obtained by lawyers that has practical influence on the defendant's conviction and sentencing is an important weight to achieve the balance between prosecution and defense; Finally, it is conducive to enhancing the comprehensiveness and authenticity of the collected evidence. Although the law requires the procuratorial organ to collect both evidence favorable to the defendant and evidence unfavorable to the defendant, in more cases, the prosecutor is concerned about whether the accusation is successful, and it is easy to ignore the collection of evidence favorable to the defendant. At this time, lawyers need to collect these evidences through the process of exercising the right to investigate and collect evidence. At the same time, the investigation activities of defense lawyers can play a supervisory role in the collection of evidence by judicial organs. Avoid illegal evidence from entering court proceedings and being accepted as judgment evidence.
Legal basis: Article 35 of the Lawyers Law of People's Republic of China (PRC). According to the needs of the case, the entrusted lawyer may apply to the people's procuratorate or the people's court for collecting and obtaining evidence or to the people's court for notifying witnesses to testify in court. If a lawyer investigates and collects evidence by himself, he may, with the lawyer's practice certificate and the certificate of the law firm, investigate the situation related to undertaking legal affairs with the relevant units or individuals.