I won't be specific. Generally speaking, only criminal suspects and defendants are blind, deaf or dumb, or mental patients who have not completely lost the ability to identify or control their own behavior, and have not entrusted defenders, the people's courts, people's procuratorates and public security organs shall notify legal aid institutions to appoint lawyers to defend them. In addition, 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.
Legal objectivity:
Criminal Procedure Law of the People's Republic of China
Article 38
Defense lawyers can provide legal aid to criminal suspects during investigation;
Acting as an agent for complaints and accusations;
Apply for changing compulsory measures;
Ask the investigation organ about the crimes and cases suspected by the criminal suspect, and put forward opinions.