It is reported that Nie Haifen is an "English model" and a famous local "female detective". Judging from the relevant introduction, she is a pre-trial police officer with delicate style and skilled business. Ironically, it was this "female detective" with extraordinary professional ability who turned a genuine "unjust case" of Uncle Zhang into an "ironclad case". Since uncle Zhang didn't commit a crime at all, there can be no "impeccable" evidence; On the contrary, this case has obvious negative evidence and a lot of doubts. For example, the details of an uncle's confession do not match; The DNA mixture detected under the victim's fingernails was tested to exclude uncles and nephews. These details should have aroused the reflection and vigilance of investigators. Regrettably, things have developed in the opposite direction, and the unjust cases have been carefully polished by "female detectives" and began to become "irrefutable evidence". With the help of "surprise interrogation" and "eyes and ears of prison investigation", uncle and nephew finally confessed, and after being lured and accused, the confession began to be consistent with the on-site investigation; As for the absence of rape traces and physical evidence, it was also "reasonably explained" through the mouth of the suspect and the opinions of the forensic doctor. Perhaps, the "female detective" is only performing the duties of the pre-examiner, trying to make the cases cracked by the criminal investigators "impeccable" in evidence, and there is no motive for deliberately creating unjust, false and wrong cases. However, in this case, the police can't shirk their responsibilities in obtaining evidence, especially in interrogation, identifying the scene and using the "eyes and ears of prison investigation". In addition, this unjust case has also profoundly warned law enforcement officers that everyone may make mistakes, and Detective is no exception. In the investigation and understanding activities, once you fall into a preconceived mindset and handle cases illegally, you will not only wronged the innocent, but also condone the bad guys.