Legal basis:
Article 37 of the Criminal Procedure Law stipulates that the defender's duty is to provide materials and opinions on whether the criminal suspect or defendant is innocent, light or relieved of criminal responsibility according to facts and laws, and to safeguard the litigation rights and other legitimate rights and interests of the criminal suspect or defendant.
Article 3 1 of the Lawyers Law, when a lawyer acts as a defender, he shall, according to the facts and laws, put forward materials and opinions on whether the criminal suspect or defendant is innocent, the crime is light or the criminal responsibility is reduced or exempted, so as to safeguard the litigation rights and other legitimate rights and interests of the criminal suspect or defendant.