Criminal lawyers can intervene in the case from the day when the criminal suspect is interrogated for the first time by the investigation organ or compulsory measures are taken. The first and second paragraphs of Article 34 of the Criminal Procedure Law stipulate that a criminal suspect has the right to entrust a defender from the day when he is interrogated for the first time by the investigation organ or takes compulsory measures. During the investigation, only lawyers can be entrusted as defenders. The defendant has the right to entrust a defender at any time. When interrogating a criminal suspect for the first time or taking compulsory measures against him, the investigation organ shall inform him that he has the right to entrust a defender. The people's procuratorate shall, within three days from the date of receiving the case materials transferred for examination and prosecution, inform the criminal suspect that he has the right to entrust a defender. The people's court shall, within three days from the date of accepting the case, inform the defendant of the right to entrust a defender. If a criminal suspect or defendant requests to entrust a defender while in custody, the people's court, the people's procuratorate and the public security organ shall promptly convey it.
Legal objectivity:
Article 37 of the Criminal Procedure Law is the responsibility of a defender to provide materials and opinions on whether a criminal suspect or defendant is innocent or light, or to reduce or exempt his 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.