Chen Shuping's move revealed the murderer's guilty conscience, but the case lacked key evidence and he could not be charged.Wu Guangqi compared the blood marks of the murder weapon on the bed sheets and mastered the basic style of the murder weapon.
Through the follow-up investigation of the suspect Chen Shuping, he discovered his criminal motive. Wu Lao analyzed that the suspect used the sound of the tape recorder to create the illusion that his wife was still alive and to provide an alibi. He further inferred that in order to create an alibi, Chen Shuping did not have the time or opportunity toAfter the murder tool was disposed of, the evidence must still be in his office, and the case was finally solved successfully.The bureau officially rehired Wu Guangqi and became the chief specially invited criminal investigation expert of the Ministry of Public Security.