二次碾压案情复杂多样，实务处理有困难，判决结果差异大，急需统一认识以达共识。本文选取前车肇事逃逸，后车二次碾压这一案件类型，主要探讨前行为人关于交通肇事罪的认定，其中逃逸及因果关系的判断为案件处理的关键。逃逸的认定应当坚持“逃避法律追究说”，同时强调救助义务的履行，结合行为人主客观方面重点考察有无逃避法律追究的故意，可从行为人是否逃离事故现场切入进行判断。应当谨防重复评价逃逸情节，若将逃逸作为定罪情节，不可再作为加重情节以升格法定刑。在判断后行为人二次碾压是否切断因果关系时，应当综合考虑事故发生时的具体情境。通常情况下，前行为人肇事后不履行法定义务而逃离事故现场，能够或者应当能够预见到被害人有被二次碾压的危险，这一危险包含在前行为人肇事逃逸所创设的危险之中，若危险得以实现应肯定前车行为与被害人伤亡结果间的因果关系。除非后车二次碾压对危害结果起到决定性作用而前车并无提供显著作用力时，则可切断因果关系，但前行为人仍需对其一次碰撞的肇事结果承担相应责任。对二次碾压前肇事逃逸人定罪量刑，应当进行具体的情境化判断。在被害人为一人，前行为人构成逃逸且承担事故主要或全部责任时，以被害人死亡时间及伤情进行分类，综合考察违章情节及因果关系，前行为人有四种可能的罪责结论：无罪、交通肇事罪基本犯、“肇事后逃逸”以及“逃逸致人死亡”。当逃逸为定罪情节，前行为人以成立交通肇事罪基本犯为主，也有无罪可能；当逃逸为加重情节，即已满足交通肇事罪基本犯的要求时，若前行为人逃逸不救助与被害人死亡结果间的因果关系得以肯定，通过对逃逸致使被害人死亡的评价，可成立“逃逸致人死亡”，否则应归为“肇事后逃逸”。无法查明被害人死亡时间的情形应坚持存疑时有利于被告原则，宜对前行为人以交通肇事罪基本犯处理。

The second collision case is complicated and varied, and it is difficult to deal with them in practice. The judgment results are quite different, so it is urgent to unify the understanding to reach a consensus. This paper selects the case type of hit-and-run of the former vehicle and the death of the victim caused by the second run-over of the latter vehicle, and mainly discusses the former actor‘s cognizance of the crime of traffic accident, in which the judgment of the escape and causality is the key to deal with the case.The identification of escape should adhere to “the theory of evading legal investigation”, at the same time, emphasize the fulfillment of the obligation of rescue, and combine the subjective and objective aspects of the actor to investigate whether there is an intention to escape legal investigation, it can be judged from whether the actor fled from the scene of the accident. If escape is regarded as a conviction circumstance, it can no longer be regarded as an aggravating circumstance to upgrade the legal punishment. When judging whether the cause-and-effect relationship is cut off or not, the specific situation of the accident should be considered comprehensively. Under normal circumstances, when the former actor leaves the scene without fulfilling his legal obligations after the accident, it can or should be able to foresee that the victim is in danger of being run over again. This risk is contained in the risk created by the hit-and-run of the former actor. If the risk can be realized, the causality between the former actor’s behavior and the result of the victim‘s injury or death should be affirmed. Unless the second collision of the latter vehicle plays a decisive role in the harm result and the former vehicle does not provide a significant force, the causal relationship can be cut off, but the former actor still needs to bear the corresponding responsibility for the accident result of his first collision.Specific situational judgment should be carried out to convict and sentence the hit-and-run person in the second collision case. When the victim is a person, the former actor constitutes escape and bears the main or full responsibility of the accident, we classify the cases according to victim‘s death time and injury situation, and investigate the violation circumstances and causality comprehensively, and there are four possible guilt conclusions for the former actor: innocence, basic crime of traffic accident, "hit-and-run" and "death caused by escape". When escape is the conviction circumstance, the former actor is mainly established as the basic crime of traffic accident, and there is also the possibility of innocence; when escape is an aggravating circumstance, that is, the hit-and-run behavior has met the requirements of the basic crime of traffic accident, if the causality between the former actor‘s escape and the result of death of the victim is confirmed, then " death caused by escape " can be established through the evaluation of the victim‘s death caused by escaping, otherwise, it should be classified as "hit-and-run". If it is impossible to find out the time of death of the victim, we should adhere to the principle of benefiting the defendant when in doubt, and should treat the former pactor as the basic crime of traffic accident.