No trace of espionage

"I don't agree with you." Wan Lilang shook his head and said, "According to what I know, it's not that Liu San is at odds with Chen Yifei and Hu Yafu, but that he is very timid and doesn't want to offend anyone, especially when it comes to official business. That was being careful, not daring to make any omissions. Therefore, he didn't dare Chen Yifei and Hu Yafu drink, and he didn't want to offend them, so he let them go and did things well by himself.

At the same time, when Chen Yifei bought back the wine and meat, Liu San could explain without asking a single question, so he didn't want to talk to them.

As for the key on Liu San's body, it seemed suspicious, but Beizhi thought it was the least suspicious.Because no one would be so foolish as to put themselves in danger of being suspected. "

Lin Chuang said: "I'm just proposing a possibility. But no matter how you say it, there are suspicions on him. Director Wan has no objection to this?"

"No problem." Wan Lilang nodded.

Putting this topic aside, Lin Chuang continued to survey the corridor.

When I walked to the west end of the corridor, I looked up and found that the eaves were recessed in a square shape, just enough for one person to go up, like an upside-down wellhead.

This should be the only way up to the roof.

Lin Chuang looked up, waved his hands to prevent others from coming, and squatted down to observe the ground carefully.

The ground was clean, free of dust and marks of any kind.

"Director Wan, call Liu San," Lin Chuang ordered.

"Yes." Wan Lilang agreed and asked someone to call.

Soon, Liu San came.

"Liu San, is there a ladder?" Lin Chuang asked, pointing to the mouth of the well above.

"Yes, I'll get it from my humble position." After Liu San finished speaking, he turned and ran down.

"Slow down." Lin Chuang shouted, and Liu San stopped.

"I'll go with you." After finishing speaking, Liu San led the way, and Lin Chuang and Liu Ermeng followed.

Wan Lilang looked at Li Shiqun, and thought to himself, "I still don't worry about Liu San."

Liu San led Lin Chuang to the east wing: "Mr. Lin, the ladder is inside."

Lin Chuang observed for a while and found that the door was unlocked, and there was a stone pavement outside the door, and no footprints could be seen.

The current technology is too backward. In future generations, footprints and fingerprints can be detected. Moreover, as long as you accidentally fall into a crime scene with even a single strand of hair, dna technology can quickly lock you.

There is no way, the only way to solve the case now is to rely on the naked eye.

Pushing open the door and looking at the ground, there was still no trace.

Looking up, I saw a narrow wooden ladder leaning against the east wall.

Lin Chuang took a closer look, wiped it with his hands, and found that there was a layer of soil on the white gloves.

But no footprints were found on the ladder.

This ruled out the possibility that the murderer used this ladder to get down from the top of the building.

……

Liu San carried the ladder and the three of them went up to the second floor.

Put the ladder under the "wellhead", climb up the ladder, push the cover of the "wellhead" with your hand, and it will be pushed away at once.

Just about to climb up, Lin Chuang stopped him: "Come down."

When Liu San came down, Lin Chuanggang was about to climb up, but Liu Er stopped him suddenly: "I'll go up."

"It's okay." Lin Chuang grabbed him and went up first.

The "well mouth" is very narrow, and can only accommodate one person. A fat man like Wu Sibao would not be able to go up at all, unless he folded his belly.

Therefore, with such a narrow "wellhead", it is easy to leave cloth threads on the edge of the well. If you are not careful, it is normal to hang a button.

Unfortunately, Lin Chuang found nothing.

When I went up to the roof, I found that the roof was covered with a thin layer of gravel.

Lin Chuang sighed, and secretly said: "This criminal environment is too good."

He straightened up, raised his head, and saw that the entire roof was connected from east to west, and it was covered with gravel.

"What the hell, the builder didn't lose money from Tongde Medical College back then, why did they get so many stones?"

……

Go back to the living room on the first floor and drive everyone out, only Li Shiqun, Lin Chuang, Wan Lilang, Liu Ermeng and Mao Yiming are there.

Lin Chuang said to Wan Lilang: "The biggest difficulty in this case is that the murderer left no trace."

"Yes, Chief Lin, there is nothing you can do with a lowly position, you must have a solution, right?" Wan Lilang glanced at Li Shiqun, seeing that he didn't talk to him at all, so he had to act as the talker.

"There are no traces, so we can only rely on logical reasoning."

"Please."

"Through investigating the scene, I have such a judgment that the murderer poisoned first, and then assassinated."

When Lin Chuang made this judgment, Li Shiqun and Wan Lilang were taken aback.

The two looked at each other, and Wan Lilang asked his question: "Mr. Lin, this, this is unlikely, right? If the murderer succeeds in poisoning, he can just kill him with poison. Why use a knife? Isn't it superfluous?" ?”

"Maybe the poison in the hands of the murderer is not poisonous enough to be fatal. In addition, maybe the underground party hates Tian Chuncai too much, so even if they kill him with poison, they still have to kill him to vent their anger."

"But, the deceased did not show signs of poisoning?"

"That's why I said that the poison in the murderer's hands is low in toxicity, or it can only stun but not kill."

"Why didn't the murderer use highly poisonous drugs?"

"I speculate that the murderer didn't want to leave traces. There are many poisons, but the most common one is arsenic. You can buy arsenic in pharmacies, but it is easy to leave traces."

"Mr. Lin, what you mean is that the murderer used a less toxic poison to stun Tian Chuncai, Chen Yifei and Hu Yafu first, and then carried out the assassination. Then, could it be an anesthetic? You know, after people are anesthetized, It can be done too."

"Correct me a little bit, Liu San was also poisoned, and he was also poisoned. Anesthetics? You mean surgical anesthetics, right? Impossible. One is that the anesthetics need to be injected, and no needle holes were seen on the corpse; two It is the murderer's original intention not to alarm the victim, and wouldn't it be contrary to his original intention to give them an injection?"

"You mean poisonous smoke or gas?"

"Yes, this is the most likely."

After Lin Chuang finished speaking, Wan Lilang fell silent, and lowered his head to think about the possibility of this.

"Is this just your conjecture? Is there any evidence?" Li Shiqun said in a neutral tone.

"Yes. First, Liu San said that he slept soundly last night. He fell asleep at ten o'clock and woke up at seven o'clock in the morning. He didn't wake up at night. Does this prove that he was also poisoned?
Second, if there is food poisoning, why are all four people poisoned?You know, the food eaten by four people is not the same.

Third, the cause of death of the three people was that their arteries were cut off.As we all know, when the artery is cut, the blood will spurt out, and the ground will be full of blood in an instant.And there were no bloody footprints left at the scene. What does this mean?It shows that the murderer didn't kill people in close quarters, but killed people with a long weapon at a little distance away.

This is not difficult to reason about.

So the question is, will the murderer attack a sane person from a distance?Even if Chen Yifei and Hu Yafu were drunk, they would scream in pain if a sharp object penetrated their flesh, wouldn't they?If it is called, will others not hear it?
fourth……. "

ah?And the fourth?