Legal analysis: lawyers have a duty to help evidence. If it is the defendant's attorney, more to the obligation to collect evidence. If the plaintiff's attorney should also be prepared, sometimes the court will require the plaintiff to also produce evidence, the plaintiff can not refuse. In civil litigation, it depends on whether there is authorization in the power of attorney, if so, then the lawyer is obliged to collect, and vice versa. In general lawyers are obliged to investigate and take evidence.
Legal basis: "the Chinese people's **** and the state criminal procedure law" article 39 the defense that in the investigation, review and prosecution period of the public security organs, the people's procuratorate to collect proof of the suspect, the defendant's innocence or mitigating circumstances of the evidence collected by the people's procuratorate has not been submitted, have the right to apply to the people's procuratorate, the people's court to retrieve.