Detective: Open your eyes, I am handcuffed in the interrogation room.

Chapter 556: Complete Evidence Chain

Hardware factory.

Sandblasting machine.

High temperature furnace.

There were indeed several key words, but at the beginning of the case, no one immediately linked them to the body, including Chen Yi.

Anyone who has killed someone knows that dealing with the corpse is the most troublesome thing.

For a person that big, it would take a lot of effort and be almost impossible to make him disappear completely from the world. The only thing he could do was to hide himself to the greatest extent possible.

Even if the body is cut into pieces, there will always be traces left behind.

Bones, flesh, hair, teeth...

How to hide?

Acid dissolution and fire are both good methods as long as the conditions are met.

The sandblasting machine can do it more thoroughly.

The working principle of the sandblasting machine is to accelerate the abrasive to the surface of the workpiece through compressed air to complete the scratching action, thereby achieving the physical effect of cleaning and strengthening the surface.

The spraying material is composed of sand and gravel such as corundum, copper sand, iron sand, etc., and has a very high hardness.

Imagine what would happen if countless hard gravel hit flesh, blood and bones at high speed.

This is much easier than dismembering a body, and it turns one into a scumbag in the truest sense of the word.

However, the use of sandblasting machines is limited. The work needs to be done in a completely sealed iron box, or outdoors wearing professional protective clothing. If used openly indoors, the user's eyes and lungs will suffer fatal damage.

There are few professionals, so the crime rate is very low on average. So far, I have not heard of any suspect using a sandblaster to deal with corpses.

Now, one should appear.

With the sandblasting machine and the high-temperature furnace, no one can expect to find any clues under the unknown premise.

However, it is impossible to reduce the body to ashes by sandblasting. A large amount of DNA will be left around, which will be evidence.

"Let go!" Kou Chaoyi was in so much pain that he broke out in a cold sweat. He looked at the police officer in charge of recording, only to find that he was just lowering his head and ignoring him, with no intention of recording anything.

"Chen Yi, I'm going to sue you!"

Chen Yi: “Answer my question.”

Kou Chaoyi said angrily: "I don't know!"

Chen Yichong waved his left hand in the observation room. Seeing this, He Shixin immediately took his people away and notified the technical detective to go to the hardware factory immediately.

The hardware factory has now been sealed off for suspected manufacture of gun parts and will be the subject of a full investigation into the second case.

In the interrogation room, Chen Yi did not waste any more time with Kou Chaoyi and left.

Kou Chaoyi was very stubborn and needed to wait for two things.

The first thing is the survey results of the hardware factory.

As long as the victim's DNA is found in the hardware factory and the chain of evidence is closed, the case can be submitted to the procuratorate for review and prosecution even without Kou Chaoyi's confession.

The second thing is Guan Xinmei’s psychological assessment and treatment results.

If Guan Xinmei could tell the truth, it would be of great help to the police in interrogating Kou Chaoyi.

One is human evidence and the other is physical evidence.

Of course it is best to have both.

Back in the office, Chen Yi called his psychologist, but no one answered.

He called Jiang Xiaoxin again and she picked up the call.

Now Jiang Xiaoxin is mainly responsible for Guan Xinmei's affairs. The two have a good chat. Relatively speaking, Guan Xinmei trusts Jiang Xiaoxin more, but she still has not provided any useful information for the case.

"Team Chen."

Chen Yi: "How is it?"

Jiang Xiaoxin was very quiet, she lowered her voice and said, "I'm waiting outside, Guan Xinmei fell asleep, Professor Liu hypnotized her.

From what Professor Liu said, Guan Xinmei doesn't seem to have Stockholm syndrome, but she definitely has psychological problems. I guess it's post-traumatic stress disorder. She refused to answer any questions about Kou Chaoyi, probably because she was afraid. "

Chen Yi: “Is it serious?”

Jiang Xiaoxin: "Professor Liu suspects it is a late-onset disease, which is more serious."

Post-traumatic stress disorder can be divided into acute, chronic and late-onset types according to the severity of the disease. The late-onset type will be very difficult to treat.

Chen Yi: "Okay, I got it. Tell me as soon as you have any news. Remember to record it."

Jiang Xiaoxin: "Understood."

After hanging up the phone, Chen Yi fell into silence.

The typical symptoms of post-traumatic stress disorder are re-experience of trauma, increased alertness, avoidance, numbness, sleep disorders and depression. Judging from Guan Xinmei's condition, avoidance and numbness are more consistent.

Claiming to know nothing about anything related to Kou Chaoyi is evasive.

Although he appears indifferent and dull on the surface, he is actually alert inside and has lost interest in most things. This is numbness.

As for the others, I haven’t figured them out yet.

Psychological experts are more professional in this area, and it seems that they have assessed that Guan Xinmei has a certain degree of depression.

There is no need for thorough treatment in a short period of time. As long as it is effective and can make Guan Xinmei tell the truth, that will be enough. The treatment of severe post-traumatic stress disorder is a long process.

I'm afraid Kou Chaoyi has done a lot of bad things to Guan Xinmei.

……

Sun Menglan's mother arrived, and the forensic doctor extracted her DNA and sent it to the laboratory for DNA paternity testing, confirming that the bloodstains found in Guan Xinmei's dormitory came from Sun Menglan.

Sun Menglan is also in danger.

Of course, the police would not tell Sun Menglan's mother about their speculation about the case. The hardware factory had not found Sun Menglan's DNA yet, so they could not say that she was dead. However, Sun Menglan's mother did not seem to care much about her daughter. When she learned that Sun Menglan could not be found, she just asked the municipal bureau to notify her when she was found, and then she left.

Because I have a young son at home who needs to be taken care of.

The police officer who received Sun Menglan's mother was a little angry. After all, she was his own daughter, and this was too careless.

We cannot interfere in other people’s family affairs and can only condemn them morally.

If not for this, Sun Menglan would not have disappeared for several years without anyone noticing. If the police had not taken the initiative to discover her, it might have remained a mystery forever.

Pitiful.

sad.

The search for Xu Chaoyue and her son has not stopped. The local police station knows that this is a case of the Municipal Bureau and is of great importance, so they have done their best to search all the relatives they can, but no one knows where the mother and son have gone.

During the period, the forensic doctor extracted DNA from Xu Chaoyue's relatives for kinship testing, and the result was the same as everyone expected. The last unknown bloodstain in Kou Chaoyi's office should have come from Xu Chaoyue's mother.

They are all relatives, so why not Xu Chaoyue? Because the bloodstains came from a woman.

From then on, the owners of the bloodstains were all identified.

The bloodstains in Guan Xinmei’s dormitory came from Sun Menglan, the former president of the Student Union.

The bloodstains in Kou Chaoyi's office came from Fu Peilan, Xu Chaoyue's mother, and Du Xun.

If none of them can be found, it means they are all dead.

As for Xu Chaoyue, our current situation is still unknown and no traces of his blood have been found anywhere.

When Xu Chaoyue went missing, a normal parent's first reaction would be to come to the school to look for her and ask questions. If there was no result, they would immediately call the police. This may be the reason for the death of Xu Chaoyue's mother.

I killed your son, and you couldn't find him and wanted to call the police, so I had to kill you again.

Both mother and son were killed. There were no other immediate family members, and no one cared that two unrelated people suddenly disappeared from the world.

Chen Yi went to the hardware factory in person to supervise the matter. Almost all forensic doctors and technical investigators came. They conducted a carpet search not only in the sandblasting machine operating room but also in the entire hardware factory.

The project is not small.

The case has been reported to the provincial department. Wei Jianfeng and the deputy director in charge attached great importance to it. In order to cooperate with the criminal investigation detachment of the municipal bureau to speed up the investigation, they also sent a trace inspection team headed by Cheng Hanjun to shorten the investigation time.

At this moment, Chen Yi was talking on the phone with Wei Jianfeng.

"There's bloodstains from four people, five people are missing, are they all dead?" Wei Jianfeng said on the phone.

Chen Yi: "I can't guarantee whether Xu Chaoyue is dead or not, but the other four are in danger. If DNA from Xu Chaoyue is found in the hardware factory, then it can be said that all five are dead."

Wei Jianfeng: "Does the suspect have a motive to kill Xu Chaoyue?"

Chen Yi: "Yes, not only do they have it, but they are the most complete among the five."

The key to the case lies in Guan Xinmei. As Guan Xinmei's boyfriend, the person Kou Chaoyi wants to kill the most must be him.

Wei Jianfeng sighed: "The result is about to come out, let's close the case as soon as possible. This matter has a huge impact, and confidentiality must be done well.

Also, try to comfort Guan Xinmei and don’t let her go out and talk nonsense. This is also what the higher-ups mean.”

It seems that the provincial department is not prepared to hold a public trial.

It is understandable that once the case is made public, it will be enough to cause a huge earthquake across the country.

It's not a question of the number of victims, but their nature.

By then, all private schools will be affected.

Chen Yi obeyed the order: "Okay, I know."

Not making it public now doesn’t mean it won’t be public in the future. Maybe after a while, everyone will know about it.

Recent cases and cases in previous years sound and feel different.

If the official announcement is about a major homicide that happened many years ago, people would just listen to it and it would become a topic of conversation after dinner. But if the official announcement is about a major homicide that happened yesterday, public opinion would explode like a fountain and cause panic.

The phone hangs up.

……

The investigation lasted for two days and two nights. The municipal bureau's laboratory was almost smoking. In the middle, the provincial department's laboratory also joined in the testing, and even the branch bureau with testing capabilities was requisitioned.

Finally, the results came out.

Everyone's DNA was found in the operation room of the hardware factory.

Everyone means this, including Xu Chaoyue.

There was no luck, no accidents, the fact is that they were all dead.

Before the interrogation, there was progress on Professor Liu's side.

Guan Xinmei spoke.

According to Jiang Xiaoxin's description, she just lay there quietly, tears streaming down her face, crying very sadly, and described in detail what Kou Chaoyi had done.

Indecency is a minor matter.

Kou Chaoyi had violated Guan Xinmei countless times in that independent dormitory over the years.

The first kill was Sun Menglan.

Sun Menglan felt resentful and jealous because of Kou Chaoyi's special care for Guan Xinmei, so she went to Guan Xinmei to settle the score. When she was being beaten, Kou Chaoyi arrived and ended Sun Menglan's life.

Used hammer.

This move was intended not only to "help" Guan Xinmei get revenge, but also to serve as a deterrent.

I can kill her, and I can kill you too, so just be obedient.

Guan Xinmei didn't know anything else. She didn't even know whether Fu Peilan was dead or alive. She suspected that her mother was dead, but she didn't dare to ask Kou Chaoyi.

Kou Chaoyi has completely controlled Guan Xinmei in all aspects, mentally and physically.

(End of this chapter)