Not all mystery novels need murder elements, but murder is usually an important plot element because it can reveal the secrets of the character's heart, promote the development of the plot, and show the social reality. Murder in mystery novels is usually a means to reveal the truth. Through murder, the reader could go deep into the hearts of the characters to understand their thoughts and motives. At the same time, murder could also increase the tension and suspense of the plot, making the readers more involved in the story. In addition, murder could also be used as a symbol of mystery novels to represent the challenges and difficulties people face in real life and how to solve these problems. Therefore, many mystery novels would use murder to show the growth of the character and the process of self-redemption.