1, lack of professional qualification: lawyers need to go through legal education and professional qualification examination before they can legally engage in legal services. Lawyers can't accept criminal cases if they don't pass the corresponding examinations and get the qualification to practice.
2. Limitation of professional field: Some lawyers focus on legal practice in specific fields, such as civil litigation and commercial law. Lawyers have no professional knowledge and experience in criminal law and are unwilling or unsuitable to accept criminal cases.
3. Conflicts of interest: Lawyers cannot accept some criminal cases because of conflicts of interest related to the cases. For example, a lawyer has relatives or business relations with the defendant or other interested parties in the case, or has represented the interests of the other party, so he cannot provide fair legal representation in the case.