1, justifiable defense, that is, criminal suspects and defendants defend themselves;
2. Entrusted defense, that is, the criminal suspect entrusts a lawyer or a close relative to defend;
3. Designated defense, that is, the defendant who may be sentenced to life imprisonment or death, or the defendant is blind, deaf, dumb or with limited capacity, and has not entrusted a defender, the court shall appoint a lawyer to defend him.
Criminal Procedure Law of the People's Republic of China
Article 19
The investigation of criminal cases shall be conducted by public security organs, except as otherwise provided by law.
Crimes such as illegal detention, extorting confessions by torture, and illegal search. The people's procuratorate may file a case for investigation of illegal acts found by judicial personnel in the process of legal supervision of litigation activities. If a major criminal case of a functionary of a state organ under the jurisdiction of a public security organ needs to be directly accepted by a people's procuratorate, it may be placed on file for investigation upon the decision of a people's procuratorate at or above the provincial level.
Cases of private prosecution are directly accepted by the people's courts.