Can't Let Go

A woman was killed in the street. Before she died, she wrote the three words "Chen Xuelin". It seemed that the murderer was right in front of her, but the police discovered that the message left by the deceased seemed to point to a university professor who had been dead for many years. After investigation, it was found that Chen Xuelin was a respectable person during his lifetime, but for some reason he was killed by his own students. As the investigation deepened, Li Zhong, the captain of the criminal police team, discovered that her death was not to prove the innocence of the deceased, but to uncover the crimes committed by the deceased. Because of her, she could not let go.