| For a long time, the police dog identification often used in criminal investigation, it is a good helper for investigators to solve the case, but in practice, the police dog identification can be used as evidence in court, the law is controversial. The author believes that from the legitimacy of the evidence, objectivity, scientific and other aspects of view, the police dog identification not have the qualification of evidence, only as a means of investigation.DNA identification is called the king of evidence in the evidence study, however, DNA identification in some cases can not be one hundred percent confirmed, even draw an ambiguous conclusion, therefore, judicial officers need to take a cautious attitude to treat the DNA identification.Determine the behavior person guilty shall be reach the "reliable, sufficient" standard of proof, the evidence proved to be no doubt, obtain the only conclusion, the formation of a closed chain of evidence, otherwise, can only make a verdict of innocence.This article takes the case of Xu Hui, focus on the analysis of the controversial evidencepolice dog identification, DNA identification, the standard of proof. The author attempts to analyze the focus of Xu Hui’s case, to further reflect on the issue behind the case: in practice, the judicial officers should thoroughly review the proof ability and the proof strength of the evidence,the evidence to be confirmed in order to prevent a chain of misjudged cases. When faced with insufficient evidence of the suspected crime case, the judicial officers should be adhering to the "presumption of innocence" judicial philosophy, adhere to make a verdict of innocence. |