According to the characteristics and behavior of the characters in the picture, some clues could be inferred, such as: 1. Identity and background information of the character in the picture: By observing the details of the character's clothing, accessories, hairstyle, etc., you can infer the character's occupation, age, gender, and other information. 2. The relationship between characters: By observing the interactions and exchanges between characters, you can infer the relationship between characters such as colleagues, friends, lovers, enemies, etc.; 3. Character's behavior: By observing the character's actions and words, you can infer the character's inner state and emotional state, such as nervousness, anxiety, anger, calmness, etc. Based on the above clues, we can infer and analyze the characters in the picture to find out who the murderer is. For example, if we believe that the murderer is the younger person in the picture, it may be because he or she is nervous or has some hidden emotions; if we believe that the murderer is the woman in the picture, it may be because she has some conflict or competition with the other two people. Through comprehensive analysis of clues and inferential analysis, we can finally come to a conclusion to find out who the murderer is. However, it should be noted that in the process of reasoning, we also need to consider some possible interference factors such as the angle of the photo, the expression of the character, lighting and other factors that will affect our reasoning results.