At the end of the day, the young policeman's words became a little choppy. The young policeman paused, and suddenly had the feeling that his mouth was suddenly open. "So, the habit of left-handers for the deceased should have been there since childhood. A habit that lasts in a person for decades has long been internalized in a person's daily behavior. Even under special circumstances, if you don't change it, you will maintain your original habits. And I can't think of a reason why the deceased deliberately changed his habit and put the water cup on his right-hand side. Based on this, I think that the final person who handled this cup should not be the deceased, but the murderer. After the young policeman finished his reasoning, he pursed his lips and nodded secretly. He saw that Wang Shen and everyone present were looking at him intently, and the pressure in his heart was slightly reduced.

"You go on, if it's a murderer, what can you deduce?" Wang Shen nodded at the young policeman and motioned for him to continue.

"If it is the murderer who washes the cup, then the purpose of the murderer should not let us find the clues left on the cup. What exactly is this residual clue? According to the clues currently in possession, it is very likely that the deceased was incapacitated. As for why you should pour another half glass of water into the cup? The murderer should have wanted to create the illusion for us that the deceased was drinking water normally. These are my inferences. The young policeman nodded lightly to Wang Shen, and when he saw Wang Shen smiling, the young policeman sat back in his chair with peace of mind.

"Xiao Liang's speculation just now is basically the same as what I thought. But just now Xiao Liang raised another question. Wang Shen also paused and glanced at everyone. What was the original liquid in the cup, and was it mixed with a drug that made the deceased lose the ability to resist? Wang Shen said as he turned his body to the projection screen again, and lightly tapped the projection screen with his finger.

The picture on the projection screen was switched again. In the picture, a carpet appears, and a water stain can be faintly seen on this carpet. "You can look at this carpet. To be precise, it should be observed for water stains on this carpet. I asked the deceased's secretary about the water stain. The deceased's secretary admitted that the water stain was related to her, explaining that the deceased had a habit of drinking coffee, and that when she went to deliver coffee in the morning, she found the deceased's body and knocked the coffee on the ground in panic. ”

"Then it seems that this secretary has a problem." Another slightly older policeman spoke out as soon as Wang Shen finished explaining what he had learned.

"Lao Li, tell me what you think." Wang Shen's eyes looked at the policeman who spoke, and he also smiled and motioned for him to continue his reasoning.

The older policeman coughed, took a sip of tea, slowed down for a moment, and then spoke: "The question of the deceased's left-handers was mentioned just now, and it is impossible for his secretary not to know about it. Therefore, every time this secretary goes to deliver coffee to the deceased, he should put the coffee on the deceased's left hand side. Now I'm going to ask you to look at the location of the water stain. It is clear that the water stain is on the right side of the office chair. This creates a contradiction. The first contradiction is that the secretary violates his habit of delivering coffee. The second contradiction is the reason for spilling coffee. The secretary said that he spilled the coffee because he saw the deceased in a panic. I was at the scene of the murder today, and if I remember correctly, the left side of the desk was facing the door to the consultation room. So there is no need for this secretary to go around to the right side of the office chair to find the deceased and then panic, this logic does not make sense at all. The normal logic is that the secretary walked into the office, walked to the left side of the desk as customary, found the deceased, and in a panic knocked over the coffee cup, and the coffee stain fell on the carpet on the left. ”

"Yes, our police force is really Crouching Tiger, Hidden Dragon. Everybody is really amazing. Wang Shen walked along the conference table to the back. I asked the identification department to do an examination of the coffee stain and came to a very important conclusion. First of all, the ingredient of the drug was indeed detected in the coffee stains. Secondly, there is another major discovery. In addition to the necessary ingredients of coffee such as caffeine and the drug components of coffee, a large amount of soap was detected in the coffee stains. To put it simply, this coffee stain has been treated. The purpose of why this coffee stain should be treated should be obvious, that is, to cover up or eliminate the residual drug ingredients in the coffee stain. But the murderer's move really adds to the problem. ”

Wang Shen walked from the back of the conference table around the other side back to the side of the projection screen. "From the information we have, the deceased should have been incapacitated by drinking this cup of coffee. As for how the coffee was later spilled on the ground, there are many possible scenarios. For example, the deceased discovered the murderer's attempt before he was completely incapacitated. At this time, the murderer happened to be standing on the right hand side of the deceased, so the deceased tried his last bit of strength to throw the coffee cup at the murderer, causing this coffee stain on the carpet. Let's leave this aside for the time being, and discuss the relationship between the murderer and the deceased. At the very least, I think the relationship between the murderer and the deceased should be familiar. Otherwise, the deceased would not have drunk the cup of coffee sent by the murderer with peace of mind. When I say this, it seems that the secretary has already been judged to be the murderer. This is somewhat hypothetical. Then I'll assume that this secretary is a suspect for the time being. ”

"But what about the motive for the killing? ...... between men and women Is it an emotional entanglement? The older policeman pinched his chin with one hand and frowned as he looked at the coffee stain on the projection screen.

"Lao Li is really experienced." Wang Shen gave a thumbs up to the older policemen. "According to the clues I have, this is indeed the case." Wang Shen clicked on the projection screen again, and the picture on the projection screen was switched again. Two pictures appeared on the projection screen, each with a cup. Everyone can see at a glance that the cups in the two pictures are a couple of cups.

"This cup." Wang Shen pointed to the picture on the left with a laser pointer. "I took it from the desk of the deceased's secretary. The secretary of the deceased should have liked this cup very much, and it was this cup that he usually used to drink water. Then, let's take a look at the cup again. The red dot of Wang Shen's laser pointer moved to the picture on the right. This cup was photographed by me in the deceased's office. The cup was placed next to the pot, and as you can see, there was a little dirt on the rim. So I guess the deceased must have used this cup for watering. A couple of cups, one is regarded as a treasure by the woman, and the other is abandoned by the man like a mustard. So what emotional entanglement should exist between this man and woman? Such entanglements are likely to be the motive for this secretary's murder. Moreover, the information I have is that the deceased's secretary was the deceased's college student and had pursued the deceased since college. ”