January 17, night.

Qin did not follow Li Xiaonan back to his office to wait, but said hello and slowly left the police station.

When Li Xiaonan smoked the third cigarette, he received a joint reply from the detectives who went out to investigate the case on the computer.

"Dear Inspector of the Polish City Police, Li Xiaonan. Since you have not initiated a formal commission or reward, we will forgive us for informing you of the results of this reasoning by email while having dinner after the investigation of the crime scene. As you said earlier. ”

"It is the detective's duty to find and reveal the truth of the mystery."

"Here's the reasoning brought to you by A-class detective tamel, please taste it."

"Aren't the members of this group of second-dimensional clubs also a little chattering?" Li Xiao couldn't think about it, and the other side continued to look through the email.

"First of all, we analyzed the results of the case, the deceased was in a secret room with doors and windows locked inside, and there was a pinhole in the back of his neck that was suspected of being injected with diazepam drugs. It can be concluded through simple logical reasoning that under the premise that the murderer cannot lock the doors and windows from the inside outside the room, then the murderer will have only one way to kill the victim - that is, after waiting for the victim to enter the room and lock the doors and windows, outside the room, through the pre-designed ambush mechanism, kill the victim, and then recover and destroy the murder weapon. ”

"If we follow this line of thinking, the first question we need to solve is how can the murderer be sure that the deceased will definitely enter the room where he has designed the killing mechanism in advance."

"I think the answer to this question lies in the question of 'identity'. The whole event was initiated by the editor-in-chief Xiao Xue, and three writers participated in the competition. Judging from the information learned as soon as he arrived at the scene, the identity of the deceased was 'Shouyang', one of the writers, and the biggest suspect was the editor-in-chief of the event, Xiao Xue. ”

"Because only the organizer of the event has the ability to manipulate or deliberately assign the deceased into a predetermined room."

"But this immediate reasoning is inconsistent with the confession, and through the narration of the only innocent witness writer, 'Zilong', the room was selected by the three writers themselves, and there was no black-box operation or assignment."

"So this suspicion was solved with the exposure of the real murderer, the 'Shouyang' disguised as Xiao Xue. That is, the identity of the deceased is the editor-in-chief Xiao Xue, and the murderer 'Shouyang' successfully exchanged identities with the deceased through the blind spot of 'the four people have not met in private' within the sight of the police. ”

"The writer's room is self-chosen, but the editor-in-chief's room is fixed."

"Combined with the fact that the door lock of room 2001 had been broken before the crime, comprehensive surveillance had captured that 'Shouyang', who called himself Xiao Xue, had arrived at the apartment a few days before the crime.

"The next question comes to the killing mechanism in the room."

"The first thing I felt when I entered the room at the scene of the crime was that the room was a bit too high, and there was only a thick beam overhead that spanned from the door to the window."

"Considering the cause of death and the location of the deceased at the time of discovery, the only way to cause this result is to hang the murder weapon on the beam of the room and then loosen the fixed rope, which can cause the cause of death in the room from a heavy blow to the head to the cranial fragment."

"So I immediately found a ladder and looked at the beams, and sure enough, I found traces of some kind of rope entanglement and rubbing."

"Another suspicion in the room is that it was filled with a large amount of animal blood that did not belong to the deceased after the incident."

"On a logical level, this is the same as the flower, a superfluous act of the murderer to show off his skills or provoke, and the purpose seems to be to render some visual impact, so as to show his cruelty or vent his emotions in a sense."

"But judging from the results of the known murderer's mental state being normal and stable, this kind of redundant action with a 'mark' style, it is enough to do one thing, then the murderer's blood filling the whole room must be a part of the whole method, and the effect of blood can only be to hide something."

"So I thought of the iron splinters that remained in the dried blood at the door."

"On the premise that I didn't find a clear murder weapon, I tentatively determined that the iron was part of the murder weapon, and the murderer transferred it from the room to the outside of the room through some method and destroyed it, so there will be a residue of iron fragments on the inside of the room door."

"The extra large amount of animal blood can't hide the remaining iron fragments, so all it can hide is bloodstains, which really belong to the blood of the dead."

"After thinking about this, I stood on the inside of the door of the room, and found that the wallpaper of this room was very problematic, because it was a retro square wallpaper superposition, it would cause some visual errors at a certain height, in order to avoid being deceived by the eyes, I climbed the ladder again, and sure enough, on the upper edge of the door frame, there was a short horizontal door edge of three to five centimeters, and above the door edge, there was a ventilation window that could be pushed inward, flush with the width of the door, and ten to fifteen centimeters high."

"And if you don't climb the ladder, you will not be able to detect the existence of the ventilation window because of the optical illusion of the wallpaper and the obstruction of the door edge."

"I also noticed that there were traces of something fixed above the edge of the door, and I checked the other side of the room and found the same marks."

"This trace can explain why the victim did not notice the murder weapon hanging above his head after entering the room, if the entire ceiling is covered with a huge sheet or something, and fixed above the door edge, then the room will visually return to the normal height of the room, so that the victim who enters the room for the first time will not notice the abnormality."

"At this point, we come to the last question, the murder weapon."

"Combine the refrigerator that acts as a high-powered battery with burned wires, plus the iron splinters that were found."

"I think the murder weapon must have been an electromagnet wrapped in a piece of cloth or a tough raincoat or something."

"Through the wire winding into an energized solenoid, and then inserted into the core, coupled with the voltage support of the high-power battery, so that the magnetic force of the electromagnet reaches extremely strong, and then in the previous arrangement, use a tough raincoat to wrap it together with a large number of iron fragments, after the circuit is connected, the iron fragments are attracted by the electromagnet to become a whole, and then before the murder, the camouflaged ceiling is uncovered from the ventilation window, the deceased is put down through the anesthetic needle, and then the camouflaged ceiling is retracted through the ventilation window, Immediately afterwards, the victim was stoned to death with a murder weapon that had been energized and magnetically attracted into an iron ball, and finally the iron ball was pulled to the ventilation window through the beam, the circuit of Unicom was closed, the magnetic force disappeared, and the wires and iron shards were recovered. ”

"At the same time, the raincoat wrapped with iron shards and electromagnets will also be stained with a large amount of blood stains of the deceased, and when the ventilation window is operated to recover the murder weapon, it will drip on the ground on the inside of the door, so after the murderer completes the operation of recovering the murder weapon, he splashes a large amount of animal blood into the room to hide the bloodstain path that really belongs to the deceased."

"And while splashing animal blood, he threw the manuscript into the room together, disguising the identity of the deceased as the writer 'Shouyang' who participated in the competition."

"If my judgment is correct, the delivery man who appeared in the confession that day has disappeared, because the large amount of iron shreds and the blood-stained raincoat used to wrap the electromagnet really disappeared from the scene of the crime, and should have been taken away and disposed of by the delivery man who came to Room 2001 in the name of food delivery."

"And the huge 'sheet' disguised as a ceiling should be kept by the murderer under the mattress in his room, after all, the delivery man's backpack is also limited, and this kind of ambiguous evidence cannot be used as physical evidence against the murderer."

At this point, the entire locked room murder case of exchanging identities has been analyzed. I think Inspector Li has already seen through it, after all, it is not an overly complicated case, but it is a loss in time and identity. ”

"If there are still unresolved doubts in this case, I think it is the murderer, that is, 'Shouyang' - Zong Ji's motive for killing. Maybe that 'Coke' will answer my question. ”

This was the end of the email, and after reading it word by word, Li Xiaonan whispered to himself: "Exactly right, Tamel." ”

Li Xiaonan didn't realize that even though he shared the answer to the puzzle with the detective by sending an email online, the corners of his mouth would unconsciously curl up.

Regardless of Li Xiaonan's identity, he really enjoys reasoning.

After a few minutes of muttering, Li Xiaonan clicked the "Reply" button on the screen: "Thank you for your reasoning, Mr. Tamel, A-class detective, it tastes very good." ”

"As for the follow-up of this case, the part about motives, I think I can answer you in this reply email."

"Just now, we successfully relented the suspect 'Coke' by charging for a box lunch, and admitted that we 'hired' Zongji to murder."

"Therefore, the 'church' is a part-time business that buys and sells crimes, can be regarded as a captive high-functioning killer, and an anti-social group organization."

"It's worth mentioning that they also provide after-sales service, and all the details that 'Coke' knows are relayed by Zongji."

"We also learned that they were hired to carry out criminal schemes, but they did not collect some money-related fees from their employer, 'Coke', but only used verbal transactions, verbal persuasion or mental hypnosis, so that 'Coke' voluntarily confessed to the police station 24 hours after the incident."

"The above is a reply to the reasoning I just received, and if possible, I still look forward to 'savoring' your wonderful reasoning in a face-to-face way."

"The prestige of this case has been sent to your card, keep an eye out, Tamel."

“...”

At this time, at a Japanese restaurant, Tamel, who was silently and quickly eliminating eel rice, checked his "prestige" balance after reading Li Xiaonan's receipt: "This time it arrives, 300 points." ”

"It's such a slam on the door..."Tamel sighed a little indignantly, "No wonder even Miya can't look down on his commission..."