Li Deshui's face suddenly became ugly, I stared at him with a sneer, I knew that he had begun to panic, although he was still pretending to be nothing, but his heart had definitely begun to mess up. Luo Feng still didn't understand, he asked me what was going on.

I glanced at Luo Feng and asked him if he remembered the tool mark on the wall in Feiji's backyard. The small crater in the wall was clearly the result of a sharp object such as the tip of a knife or an iron nail colliding with a smooth brick wall coated with cement. According to my surmisath, I think it was a knife that flew into Fatty Ji's throat and hit the wall.

Fat Ji is a policeman, his vigilance is very high, although he is fat, but he is definitely not a person who is attacked by others and can't even resist. However, there was no sign of struggle at the scene, and the grass was not trampled, only a patch of weeds that had been flattened when the fertilizer base fell.

Therefore, the murderer must not have had close contact with Feiji, otherwise Feiji would not have been killed with one blow. This reasoning is reasonable, and the only doubt is Luo Feng's suspicion. Luo Feng questioned who could throw a knife out and cut the throat of the fat base so accurately, and finally collided with the wall and left work marks.

At that time, I knew that this was something that could not be done by manpower. According to my speculation, the knife flew out of the big tree, and after cutting the throat of the fat base, it could also collide with the wall, leaving work marks, which shows that the knife flew very fast, and the force that made the knife fly out was also very large.

One person, absolutely can't do it. So, when I was in the backyard of Hiki's house, I speculated that it was the result of props, but for a while, I couldn't think of any props that could do it. Now, when I zeroed in on the suspect Li Deshui, some things can be perfectly explained.

Li Deshui is a magician, and all kinds of performances of magicians, in addition to using superb techniques that can hide people's attention, also need some props that seem simple, but actually hide mysteries. Magic show is a creative art show, magicians can't just perform those classic magic tricks forever, they need to create new magic tricks.

In the process of creation, the magician had to make various props. Therefore, making props is not difficult for Li Deshui. I walked up to Li Deshui again and said to him expressionlessly: "You have already sneaked into Feiji's house, you must have made precise measurements on the spot." ”

Only by measuring it with precision can we create a tool or mechanism that has the least error in actual operation. I speculate that what makes the knife fly out is elasticity, and it is likely that Li Deshui installed a spring device that can eject the knife on the big tree in advance.

The spring device, perhaps with a string or something, is connected to something on the ground. As soon as the object on the ground is touched, the spring mechanism is also touched at the same time, and the knife is ejected. The knife was able to cut Fei Ji's throat accurately, and it must have been because Fei Ji went to the position that Li Deshui had calculated in advance and touched the device on the ground.

The place where Feiji fell, there was an absorbent blanket, and after Feiji walked into the backyard, he would definitely find the blanket if he looked closely. So, I speculate that the absorbent blanket is the switch that touches the spring device. According to normal people's thinking, if they find a blanket in the yard, they will go over to investigate.

Li Deshui used some sounds or phenomena to lead the fat base of returning home to the backyard. At that time, as a fat base for the police, he was definitely vigilant. However, when he arrived in the backyard, he didn't find anyone, only a blanket on top of the weeds.

I think Fei Ji must have carefully gone over to investigate. However, who would have thought that a blanket would bring death to himself. Perhaps, it was because Feiji stepped on the blanket, or perhaps, it was Feiji who squatted down and lifted the blanket, thus touching the spring mechanism connected by a thin wire, and the knife flew out like that.

"Mr. Li, am I right?" I pinched Li Deshui's chin with my hand: "You must be very good at making props, this is what you use to kill, right?" ”

Li Deshui's face darkened, and he shook off my hand. He still didn't admit it, he asked me rhetorically: "Even if it's like what you said, how can I know whether Feiji will step on that blanket or lift that blanket, one is standing and the other is squatting, who can guarantee that in both cases, the knife can cut his throat?" ”

"Mr. Li, have you ever heard of a sentence?" I suddenly asked a question.

Li Deshui didn't speak, waiting for me to speak. I just scoffed: "The more expert you are, the more you can find problems." ”

Li Deshui snorted coldly: "If you want to add to the crime, there is no excuse!" You think I'm a murderer, everything is aimed at me, what the hell do you want to do! ”

Seeing that Li Deshui looked very confident, I shook my head: "For a magician, it is not difficult to set two different switches on the same prop." I stared into Li Deshui's eyes, and at first, he could still make eye contact with me, but slowly, he looked away.

I speculate that there are two thin wires that connect the spring device to the blanket. One activates the spring mechanism when the blanket is lifted and flies towards the squatting manga, while the other, when the blanket is under pressure, activates the mechanism and flies towards the fatbase standing and stepping on the blanket.

The fat base is relatively large, which increases the probability of hitting the knife. The direction of the knife flying, Li Deshui has definitely calculated and predicted it precisely in advance. Perhaps, at the beginning, he didn't necessarily want to cut the throat of the fat base, but set the target for the head of the fat base, which is absolutely fatal.

Cutting the throat also carries an element of luck. If it only hits Feiji's head, even if it can't be fatal with one blow, it will be easy for Li Deshui, who is hiding in the shadows, to come out and kill Feiji again. Perhaps, even Li Deshui didn't expect that the knife would directly cut Feiji's throat and make him lose his life.

Because of this, the weeds leave misty blood stains. Blood in the throat spurted out, sometimes up to two meters away, and Li Deshui spread an absorbent blanket just to avoid leaving blood. He didn't expect that the knife would directly cut Feiji's throat, and he didn't know that the blood in his throat would spurt so far, so there were clues that we could detect.

Luo Feng listened very carefully, he walked up to my side and asked softly in my ear: "Fang Han, don't you want to say that he is the inevitability of the murderer, what you are talking about is still a possibility." ”

In the face of Luo Feng's reminder, I just smiled slightly. Indeed, so far, all I have said is the possibility that Li Deshui is the murderer. Logical reasoning in investigation is divided into possibility and inevitability, and the possibility is generally reverse reasoning, that is, assuming that a person is a criminal suspect, and then inferring whether this person can complete the crime according to the suspect's identity, occupation, personality and other characteristics.

As for inevitability, it is positive reasoning, that is, based on a clue or trace evidence, it is concluded that a person must be the murderer.

Li Deshui's identity as a magician allowed him to complete this crime. Previously, I also speculated that the murderer was a thoughtful person based on the perspective of criminal psychology portrait, and his profession or personality was related to innovation. The magician, which is also completely in line with the character portrait of the murderer I depicted.

With a few rolls of transparent glue, I can let him escape from my hands, and play simple things with tricks, which is also in line with the magician's tricks. Coupled with the fact that Li Deshui is a native of the rural village, and the behavior and reaction of Li Deshui who made a mistake in his performance and suddenly disappeared from work time during the day and night when we went to the countryside, I was enough to conclude that he was the murderer I was going to find out.

Now, only evidence is needed to convict Li Deshui.

Li Deshui laughed loudly, and he also heard Luo Feng's reminder to me. Li Deshui looked at his watch, he said that he was going to get on the boat, Li Deshui still felt that Luo Feng didn't dare to kill him, and I had no evidence to arrest him, so he wanted to go. My voice was cold again: "I remember reminding you once, I don't like people interrupting me. ”

As soon as my words fell, I snatched the knife in Luo Feng's hand and cut Li Deshui's chest. My strength was just right, and Li Deshui only suffered a skin injury. Li Deshui covered his wound and stared at me in surprise, he didn't expect me to make a move. I returned the knife to Luo Feng: "Now, it's time to talk about what happened to the food in the stomachs of Lao Jiu and the others." ”

Li Deshui's face was even more ugly, and his expression was all under my eyes.

According to the forensic autopsy report of the Police Identification Section, the food in the deceased's stomach had only minor chemical changes and was not digested. This is the difficulty of the police to solve the case, they can't figure out when the food was eaten. If it is eaten before death, the food will not be undigested, and if it is eaten after death, the case must be attributed to the theory of ghosts and gods, because after death, the peristalsis of the esophagus stops, and the food will never reach the stomach.

In fact, the police have made many speculations, but each one has been denied in the end.

When I first read the dossier, I also speculated. I speculate that food is eaten at the time of life and death, and that the peristalsis of the esophagus is still working when the person is dying, but only slightly and subtly. At that time, when people are fed, food can still enter the esophagus through the pharyngeal organ.

The pharynx is an important organ for human eating and breathing, and it is both a respiratory organ and a digestive organ.

When a person is breathing, the pharynx will cause the esophagus to close, and when a person is swallowing and eating, the pharynx will cause apnea, and in general, swallowing and breathing cannot be carried out at the same time.

Food passes through the pharynx, which is almost a conditioned reflex, and the food enters the esophagus.