1, the suspect or defendant is a minor;
2. The criminal suspect or defendant is blind, deaf, dumb or mentally ill;
3. The suspect or defendant may be sentenced to life imprisonment or death penalty.
In the above three cases, if the suspect or defendant has no lawyer to defend, the case-handling organ will notify the legal aid institution to appoint a lawyer to defend him, otherwise the legal procedure is illegal.
According to the law, the defender's duty is to put forward materials and opinions to prove the innocence, lighten or reduce or exempt criminal responsibility of criminal suspects and defendants according to facts and laws, and safeguard the legitimate rights and interests of criminal suspects and defendants. At the same time, before the final result of the case is made, no one except the case-handling organ and the defense lawyer is allowed to meet the criminal suspect, and of course it is impossible to provide legal help to him. Therefore, in order to safeguard the legitimate rights and interests of criminal suspects and strive to reduce or exempt punishment, it is suggested to entrust a lawyer to provide legal aid as soon as possible.
The above is my answer to this question, hoping to help you.
Legal basis:
Article 35 of the Criminal Procedure Law of People's Republic of China (PRC)
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.