Both the defendant's lawyer and the plaintiff's lawyer can find each other to investigate.
Relevant laws and regulations: Article 35 of the new Lawyers Law stipulates: "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 according to the needs of the case; 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.
It can be seen that lawyers have the right to investigate and collect evidence on their own, and only need "two certificates", and only those who meet with criminal suspects or defendants need "three certificates" (lawyer's practice certificate, law firm certificate, power of attorney or legal aid letter).
However, although there are clear provisions in the law, it is generally difficult for lawyers to obtain evidence on their own, and defendants are often unwilling to cooperate. If criminal cases are involved, lawyers may have to bear their own personal risks.
According to the relevant answers to the above contents,
The entrusted lawyer may, according to the needs of the case, apply to the people's procuratorate or the people's court to collect and obtain evidence or apply to the people's court to notify witnesses to testify in court.
Lawyers who investigate and collect evidence by themselves can only rely on the lawyer's practice license and the certificate of the law firm.