在刑事诉讼中,警察鉴定人与警察证人具有不同的诉讼地位,警察鉴定人不可兼具双重诉讼地位。警察证人就有关案件部分实体事实和程序事实向法庭作出证词,证明警务行为的合法性和合理性,警察鉴定人从事科学实证活动,具有独立和超然的科学认知、中立于诉讼价值判断的地位。警察鉴定人出庭的目的就是自信地显明鉴定资格身份,表明鉴定人个人人格公正性的极可信赖,详细论证鉴定结论的前导原因并作出解释。 In criminal proceedings, police appraisers and police witnesses have different litigation status, and police appraisers can not have dual litigation status. The police witness testified to the court on the facts and procedural facts about some of the cases to prove the legitimacy and rationality of the police act. The police appraisers engaged in the scientific evidence-based activities with independent and detached scientific cognitions and stood in the judgment of litigation value . The purpose of the police appraisers to appear in court is to confidently demonstrate the qualifications of appraisals and demonstrate the trustworthiness of the appraisers’ personal personality. The reasons for appraisal conclusions are explained in detail and explained.