Legal basis: People's Republic of China (PRC) Lawyers Law.
Article 28 A lawyer may engage in the following businesses: (3) Entrusted by a criminal suspect or defendant in a criminal case or a defender appointed by a legal aid institution according to law, entrusted by a private prosecutor in a private prosecution case, a victim in a public prosecution case or his near relatives to act as an agent and participate in litigation;
Article 31 When acting as a defender, a lawyer shall, according to facts and laws, put forward materials and opinions on acquittal, lighter punishment or reduction or exemption of criminal responsibility of criminal suspects and defendants, so as to protect the litigation rights and other legitimate rights and interests of criminal suspects and defendants.