关键词: 关键词：公安机关, 侦查错误, 刑事鉴定制度, 完善

Abstract:   Criminal appraisal plays an increasingly important role in solving criminal cases by police. The public security organs rely heavily on criminal appraisal in finding investigation clues and evidence. Due to the defect in criminal appraisal by public security organs, many problems, such as investigation errors and injustice cases, may occur. In order to improve current criminal appraisal by public security organs, we need to address the issue of the organizational and administrative system of internal expertise organization in public security organs, which means to ensure the independence of internal expertise organizations. Meanwhile we should set clear standards for acceptance of criminal appraisal technology. It is true that the improvement of criminal appraisal by public security organs cannot completely eradicate investigation errors but it can reduce the probability of their occurrence.

Key words: Key words: public security organs, investigation errors, criminal identification system, improvement