legal ground
Article 35 of the Criminal Procedure Law
If a criminal suspect or defendant fails to entrust a defender due to financial difficulties or other reasons, he or his close relatives may apply to a legal aid institution. To meet the conditions of legal aid, legal aid institutions shall appoint lawyers to defend them.
If the criminal suspect or defendant is a mental patient who is blind, deaf, dumb or has not completely lost the ability to identify or control his own behavior, and has not entrusted a defender, the people's court, the people's procuratorate and the public security organ shall notify the legal aid institution to appoint a lawyer to defend him.
If a criminal suspect or defendant may be sentenced to life imprisonment or death without entrusting a defender, the people's court, the people's procuratorate and the public security organ shall notify the legal aid institution to appoint a lawyer to defend him.